Copyright (c) 1994 Association of Mizar Users
environ vocabulary FUNCT_1, PBOOLE, TDGROUP, CARD_3, RELAT_1, MSUALG_2, PRALG_1, REALSET1, BOOLE, ZF_REFLE, PROB_1, TARSKI, AMI_1, MSUALG_1, FREEALG, PRELAMB, ALG_1, FINSEQ_1, QC_LANG1, LANG1, DTCONSTR, TREES_4, TREES_2, TREES_3, FUNCT_6, MCART_1, UNIALG_2, GROUP_6, MSUALG_3, MSAFREE, FINSEQ_4; notation TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, XREAL_0, NAT_1, RELAT_1, RELSET_1, STRUCT_0, FUNCT_1, MCART_1, FUNCT_2, FINSEQ_1, FINSEQ_2, TREES_2, PROB_1, CARD_3, FINSEQ_4, LANG1, TREES_3, FUNCT_6, TREES_4, DTCONSTR, PBOOLE, PRALG_1, MSUALG_1, MSUALG_2, MSUALG_3; constructors NAT_1, MCART_1, MSUALG_3, FINSOP_1, FINSEQ_4, FINSEQOP, PROB_1, MEMBERED, XBOOLE_0; clusters SUBSET_1, FUNCT_1, FINSEQ_1, PBOOLE, TREES_3, TREES_4, DTCONSTR, PRALG_1, MSUALG_1, MSUALG_3, RELSET_1, STRUCT_0, XBOOLE_0, ARYTM_3, MEMBERED, ZFMISC_1, NUMBERS, ORDINAL2; requirements NUMERALS, BOOLE, SUBSET; definitions TARSKI, XBOOLE_0, PBOOLE, MSUALG_3, STRUCT_0; theorems TARSKI, FUNCT_1, FUNCT_2, MCART_1, ZFMISC_1, PBOOLE, CARD_3, MSUALG_1, MSUALG_2, MSUALG_3, PRALG_1, RELAT_1, LANG1, DTCONSTR, FINSEQ_1, TREES_4, FINSEQ_4, TREES_1, TREES_2, ALG_1, DOMAIN_1, PROB_1, RELSET_1, XBOOLE_0, XBOOLE_1; schemes ZFREFLE1, FUNCT_1, RELSET_1, MSUALG_2, DTCONSTR, COMPTS_1, XBOOLE_0; begin :: :: Preliminaries :: theorem Th1: for I be set, J be non empty set, f be Function of I,J*, X be ManySortedSet of J, p be Element of J*, x be set st x in I & p = f.x holds (X# * f).x = product (X * p) proof let I be set, J be non empty set, f be Function of I,J*, X be ManySortedSet of J, p be Element of J*, x be set; assume A1: x in I & p = f.x; A2: dom f = I & rng f c= J* by FUNCT_2:def 1,RELSET_1:12; then dom (X# * f) = dom f by PBOOLE:def 3; hence (X# * f).x =(X# qua ManySortedSet of J*).p by A1,A2,FUNCT_1:22 .= product (X * p) by MSUALG_1:def 3; end; definition let I be set, A,B be ManySortedSet of I, C be ManySortedSubset of A, F be ManySortedFunction of A,B; func F || C -> ManySortedFunction of C,B means :Def1: for i be set st i in I for f be Function of A.i,B.i st f = F.i holds it.i = f | (C.i); existence proof defpred P[set,set] means for f be Function of A.$1,B.$1 st f = F.$1 holds $2 = f | (C.$1); A1: for i be set st i in I ex u be set st P[i,u] proof let i be set; assume i in I; then reconsider f = F.i as Function of A.i,B.i by MSUALG_1:def 2; take f | (C.i); thus thesis; end; consider H be Function such that A2: dom H = I & for i be set st i in I holds P[i,H.i] from NonUniqFuncEx(A1); reconsider H as ManySortedSet of I by A2,PBOOLE:def 3; for i be set st i in I holds H.i is Function of C.i,B.i proof let i be set; assume A3: i in I; then reconsider f = F.i as Function of A.i,B.i by MSUALG_1:def 2; A4: H.i = f | (C.i) by A2,A3; C c= A by MSUALG_2:def 1; then A5: C.i c= A.i by A3,PBOOLE:def 5; per cases; suppose A6: B.i is empty; set h = f | (C.i); rng h c= B.i by RELSET_1:12; then rng h = {} by A6,XBOOLE_1:3; then A7: H.i = {} by A4,RELAT_1:64; now per cases; suppose C.i = {}; hence thesis by A7,FUNCT_2:55,RELAT_1:60; suppose C.i <> {}; hence thesis by A6,A7,FUNCT_2:def 1,RELSET_1:25; end; hence thesis; suppose A8: B.i is non empty; then A9: dom f = A.i & rng f c= B.i by FUNCT_2:def 1,RELSET_1:12; A10: dom (f|(C.i)) = dom f /\ (C.i) by FUNCT_1:68 .= C.i by A5,A9,XBOOLE_1:28; rng (f|(C.i)) c= B.i by RELSET_1:12; hence thesis by A4,A8,A10,FUNCT_2:def 1,RELSET_1:11; end; then reconsider H as ManySortedFunction of C,B by MSUALG_1:def 2; take H; thus thesis by A2; end; uniqueness proof let X,Y be ManySortedFunction of C,B;assume that A11: for i be set st i in I for f be Function of A.i,B.i st f = F.i holds X.i = f | (C.i) and A12: for i be set st i in I for f be Function of A.i,B.i st f = F.i holds Y.i = f | (C.i); for i be set st i in I holds X.i = Y.i proof let i be set; assume A13: i in I; then reconsider f = F.i as Function of A.i,B.i by MSUALG_1:def 2; X.i = f|(C.i) & Y.i = f|(C.i) by A11,A12,A13; hence thesis; end; hence thesis by PBOOLE:3; end; end; definition let I be set, X be ManySortedSet of I, i be set; assume A1: i in I; func coprod(i,X) -> set means :Def2: for x be set holds x in it iff ex a be set st a in X.i & x = [a,i]; existence proof defpred P[set] means ex a be set st a in X.i & $1 = [a,i]; consider A be set such that A2: for x be set holds x in A iff x in [:X.i,I:] & P[x] from Separation; take A; let x be set; thus x in A implies ex a be set st a in X.i & x = [a,i] by A2; given a be set such that A3: a in X.i & x = [a,i]; x in [:X.i,I:] by A1,A3,ZFMISC_1:106; hence thesis by A2,A3; end; uniqueness proof let A,B be set;assume that A4: for x be set holds x in A iff ex a be set st a in X.i & x = [a,i] and A5: for x be set holds x in B iff ex a be set st a in X.i & x = [a,i]; thus A c= B proof let x be set; assume x in A; then ex a be set st a in X.i & x = [a,i] by A4; hence thesis by A5; end; let x be set; assume x in B; then ex a be set st a in X.i & x = [a,i] by A5; hence thesis by A4; end; end; definition let I be set, X be ManySortedSet of I; redefine func disjoin X -> ManySortedSet of I means :Def3: for i be set st i in I holds it.i = coprod(i,X); coherence proof dom X = I by PBOOLE:def 3; hence dom disjoin X = I by CARD_3:def 3; end; compatibility proof let IT be ManySortedSet of I; hereby assume A1: IT = disjoin X; let i be set; assume A2: i in I; then i in dom X by PBOOLE:def 3; then A3: IT.i = [:X.i,{i}:] by A1,CARD_3:def 3; now let x be set; hereby assume x in IT.i; then consider a,b being set such that A4: a in X.i & b in {i} and A5: x = [a,b] by A3,ZFMISC_1:def 2; take a; thus a in X.i by A4; thus x = [a,i] by A4,A5,TARSKI:def 1; end; given a being set such that A6: a in X.i and A7: x = [a,i]; i in {i} by TARSKI:def 1; hence x in IT.i by A3,A6,A7,ZFMISC_1:def 2; end; hence IT.i = coprod(i,X) by A2,Def2; end; assume A8: for i be set st i in I holds IT.i = coprod(i,X); A9: dom IT = I by PBOOLE:def 3; then A10: dom IT = dom X by PBOOLE:def 3; now let x be set; assume A11: x in dom X; then A12: x in I by PBOOLE:def 3; A13: now let a be set; hereby assume a in coprod(x,X); then consider b being set such that A14: b in X.x and A15: a = [b,x] by A12,Def2; x in {x} by TARSKI:def 1; hence a in [:X.x,{x}:] by A14,A15,ZFMISC_1:def 2; end; assume a in [:X.x,{x}:]; then consider a1,a2 being set such that A16: a1 in X.x & a2 in {x} and A17: a = [a1,a2] by ZFMISC_1:def 2; a2 = x by A16,TARSKI:def 1; hence a in coprod(x,X) by A12,A16,A17,Def2; end; thus IT.x = coprod(x,X) by A8,A9,A10,A11 .= [:X.x,{x}:] by A13,TARSKI:2; end; hence IT = disjoin X by A10,CARD_3:def 3; end; synonym coprod X; end; definition let I be non empty set, X be non-empty ManySortedSet of I; cluster coprod X -> non-empty; coherence proof now let x be set; assume x in I; then reconsider i = x as Element of I; A1: (coprod X).i = coprod(i,X) by Def3; consider a be set such that A2: a in X.i by XBOOLE_0:def 1; [a,i] in (coprod X).i by A1,A2,Def2; hence (coprod X).x is non empty; end; hence thesis by PBOOLE:def 16; end; end; definition let I be non empty set, X be non-empty ManySortedSet of I; cluster Union X -> non empty; coherence proof consider i be Element of I; consider a be set such that A1: a in X.i by XBOOLE_0:def 1; dom X = I by PBOOLE:def 3; then X.i in rng X by FUNCT_1:def 5; then a in union rng X by A1,TARSKI:def 4; hence thesis by PROB_1:def 3; end; end; theorem for I be set, X be ManySortedSet of I, i be set st i in I holds X.i <> {} iff (coprod X).i <> {} proof let I be set, X be ManySortedSet of I, i be set; assume A1: i in I; then A2: (coprod X).i = coprod(i,X) by Def3; thus X.i <> {} implies (coprod X).i <> {} proof assume X.i <> {}; then consider x be set such that A3: x in X.i by XBOOLE_0:def 1; [x,i] in (coprod X).i by A1,A2,A3,Def2; hence thesis; end; assume (coprod X).i <> {}; then consider a be set such that A4: a in coprod(i,X) by A2,XBOOLE_0:def 1; consider x be set such that A5: x in X.i & a = [x,i] by A1,A4,Def2; thus thesis by A5; end; begin :: :: Free Many Sorted Universal Algebra - General Notions :: reserve S for non void non empty ManySortedSign, U0 for MSAlgebra over S; definition let S be non void non empty ManySortedSign, U0 be MSAlgebra over S; mode GeneratorSet of U0 -> MSSubset of U0 means :Def4: the Sorts of GenMSAlg(it) = the Sorts of U0; existence proof set A = the Sorts of U0; reconsider A as MSSubset of U0 by MSUALG_2:def 1; take A; set G = GenMSAlg(A); A is MSSubset of G by MSUALG_2:def 18; then A1: A c= the Sorts of G by MSUALG_2:def 1; the Sorts of G is MSSubset of U0 by MSUALG_2:def 10; then the Sorts of G c= A by MSUALG_2:def 1; hence thesis by A1,PBOOLE:def 13; end; end; theorem for S be non void non empty ManySortedSign, U0 be strict non-empty MSAlgebra over S, A be MSSubset of U0 holds A is GeneratorSet of U0 iff GenMSAlg(A) = U0 proof let S be non void non empty ManySortedSign, U0 be strict non-empty MSAlgebra over S, A be MSSubset of U0; thus A is GeneratorSet of U0 implies GenMSAlg(A) = U0 proof assume A1: A is GeneratorSet of U0; reconsider U1 = U0 as MSSubAlgebra of U0 by MSUALG_2:6; the Sorts of GenMSAlg(A) = the Sorts of U1 by A1,Def4; hence thesis by MSUALG_2:10; end; assume GenMSAlg(A) = U0; hence thesis by Def4; end; definition let S,U0; let IT be GeneratorSet of U0; attr IT is free means :Def5: for U1 be non-empty MSAlgebra over S for f be ManySortedFunction of IT,the Sorts of U1 ex h be ManySortedFunction of U0,U1 st h is_homomorphism U0,U1 & h || IT = f; end; definition let S be non void non empty ManySortedSign; let IT be MSAlgebra over S; attr IT is free means :Def6: ex G being GeneratorSet of IT st G is free; end; theorem Th4: for S be non void non empty ManySortedSign, X be ManySortedSet of the carrier of S holds Union coprod X misses [:the OperSymbols of S,{the carrier of S}:] proof let S be non void non empty ManySortedSign, X be ManySortedSet of the carrier of S; assume Union (coprod X) /\ [:the OperSymbols of S,{the carrier of S}:] <> {} ; then consider x be set such that A1: x in Union (coprod X) /\ [:the OperSymbols of S,{the carrier of S}:] by XBOOLE_0:def 1; A2: x in Union (coprod X) & x in [:the OperSymbols of S,{the carrier of S}:] by A1,XBOOLE_0:def 3; then x in union rng (coprod X) by PROB_1:def 3; then consider A be set such that A3: x in A & A in rng (coprod X) by TARSKI:def 4; consider s be set such that A4: s in dom (coprod X) & (coprod X).s = A by A3,FUNCT_1:def 5; reconsider s as SortSymbol of S by A4,PBOOLE:def 3; A5: s in the carrier of S; A = coprod(s,X) by A4,Def3; then consider a be set such that A6: a in X.s & x = [a,s] by A3,Def2; s in {the carrier of S} by A2,A6,ZFMISC_1:106; then s = the carrier of S by TARSKI:def 1; hence contradiction by A5; end; begin :: :: Construction of Free Many Sorted Algebras for Given Signature :: definition let S be non void ManySortedSign; cluster the OperSymbols of S -> non empty; coherence by MSUALG_1:def 5; end; definition let S be non void non empty ManySortedSign, X be ManySortedSet of the carrier of S; canceled 2; func REL(X) -> Relation of ([:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X)), (([:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X))*) means :Def9: for a be Element of [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X), b be Element of ([:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X))* holds [a,b] in it iff a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)); existence proof set O = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X); defpred P[Element of O,Element of O*] means $1 in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = $1 holds len $2 = len (the_arity_of o) & for x be set st x in dom $2 holds ($2.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = $2.x holds the_result_sort_of o1 = (the_arity_of o).x) & ($2.x in Union (coprod X) implies $2.x in coprod((the_arity_of o).x,X)); consider R be Relation of O,O* such that A1: for a be Element of O, b be Element of O* holds [a,b] in R iff P[a,b] from Rel_On_Dom_Ex; take R; let a be Element of O, b be Element of O*; thus [a,b] in R implies a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)) by A1; assume a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)); hence thesis by A1; end; uniqueness proof set O = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X); let R,P be Relation of O,O*; assume that A2: for a be Element of O, b be Element of O* holds [a,b] in R iff a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)) and A3: for a be Element of O, b be Element of O* holds [a,b] in P iff a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)); for x,y be set holds [x,y] in R iff [x,y] in P proof let x,y be set; thus [x,y] in R implies [x,y] in P proof assume A4: [x,y] in R; then reconsider a = x as Element of O by ZFMISC_1:106; reconsider b = y as Element of O* by A4,ZFMISC_1:106; [a,b] in R by A4; then a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)) by A2; hence thesis by A3; end; assume A5: [x,y] in P; then reconsider a = x as Element of O by ZFMISC_1:106; reconsider b = y as Element of O* by A5,ZFMISC_1:106; [a,b] in P by A5; then a in [:the OperSymbols of S,{the carrier of S}:] & for o be OperSymbol of S st [o,the carrier of S] = a holds len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)) by A3; hence thesis by A2; end; hence thesis by RELAT_1:def 2; end; end; reserve S for non void non empty ManySortedSign, X for ManySortedSet of the carrier of S, o for OperSymbol of S, b for Element of ([:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X))* ; theorem Th5: [[o,the carrier of S],b] in REL(X) iff len b = len (the_arity_of o) & for x be set st x in dom b holds (b.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.x holds the_result_sort_of o1 = (the_arity_of o).x) & (b.x in Union (coprod X) implies b.x in coprod((the_arity_of o).x,X)) proof defpred P[OperSymbol of S,Element of ([:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X))*] means len $2 = len (the_arity_of $1) & for x be set st x in dom $2 holds ($2.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = $2.x holds the_result_sort_of o1 = (the_arity_of $1).x) & ($2.x in Union (coprod X) implies b.x in coprod((the_arity_of $1).x,X)); set a = [o,the carrier of S]; the carrier of S in {the carrier of S} by TARSKI:def 1; then A1: a in [:the OperSymbols of S,{the carrier of S}:] by ZFMISC_1:106; then reconsider a as Element of [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X) by XBOOLE_0:def 2; thus [[o,the carrier of S],b] in REL(X) implies P[o,b] proof assume [[o,the carrier of S],b] in REL(X); then for o1 be OperSymbol of S st [o1,the carrier of S] = a holds P[o1,b] by Def9; hence thesis; end; assume A2: P[o,b]; now let o1 be OperSymbol of S; assume [o1,the carrier of S] = a; then o1 = o by ZFMISC_1:33; hence P[o1,b] by A2; end; hence thesis by A1,Def9; end; definition let S be non void non empty ManySortedSign, X be ManySortedSet of the carrier of S; func DTConMSA(X) -> DTConstrStr equals :Def10: DTConstrStr (# [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X), REL(X) #); correctness; end; definition let S be non void non empty ManySortedSign, X be ManySortedSet of the carrier of S; cluster DTConMSA(X) -> strict non empty; coherence proof DTConMSA(X) = DTConstrStr (# [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X), REL(X) #) by Def10; hence DTConMSA X is strict & the carrier of DTConMSA(X) is non empty; end; end; theorem Th6: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S holds NonTerminals(DTConMSA(X)) = [:the OperSymbols of S,{the carrier of S}:] & Terminals (DTConMSA(X)) = Union (coprod X) proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; A1: Union(coprod X) misses [:the OperSymbols of S,{the carrier of S}:] by Th4; set D = DTConMSA(X), A = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)); A2: D = DTConstrStr (# A , REL(X) #) by Def10; A3: the carrier of D = (Terminals D) \/ (NonTerminals D) & (Terminals D) misses (NonTerminals D) by DTCONSTR:8,LANG1:1; thus A4: NonTerminals D c= [:the OperSymbols of S,{the carrier of S}:] proof let x be set; assume x in NonTerminals D; then x in { s where s is Symbol of D: ex n being FinSequence st s ==> n} by LANG1:def 3; then consider s be Symbol of D such that A5: s = x & ex n being FinSequence st s ==> n; consider n be FinSequence such that A6: s ==> n by A5; A7: [s,n] in the Rules of D by A6,LANG1:def 1; reconsider s as Element of A by A2; reconsider n as Element of A* by A2,A7,ZFMISC_1:106; [s,n] in REL X by A2,A6,LANG1:def 1; hence thesis by A5,Def9; end; thus A8: [:the OperSymbols of S,{the carrier of S}:] c= NonTerminals D proof let x be set; assume A9: x in [:the OperSymbols of S,{the carrier of S}:]; then consider o being OperSymbol of S, x2 being Element of {the carrier of S} such that A10: x = [o,x2] by DOMAIN_1:9; A11: the carrier of S = x2 by TARSKI:def 1; then reconsider xa = [o,the carrier of S] as Element of (the carrier of D) by A2,A9,A10,XBOOLE_0:def 2; set O = the_arity_of o; defpred P[set,set] means $2 in coprod (O.$1,X); A12: for a be set st a in Seg len O ex b be set st P[a,b] proof let a be set; assume a in Seg len O; then a in dom O by FINSEQ_1:def 3; then A13: O.a in rng O & rng O c= the carrier of S by FINSEQ_1:def 4,FUNCT_1:def 5; then X.(O.a) is non empty by PBOOLE:def 16; then consider x be set such that A14: x in X.(O.a) by XBOOLE_0:def 1; take y = [x,O.a]; thus y in coprod(O.a,X) by A13,A14,Def2; end; consider b be Function such that A15: dom b = Seg len O & for a be set st a in Seg len O holds P[a,b.a] from NonUniqFuncEx(A12); reconsider b as FinSequence by A15,FINSEQ_1:def 2; rng b c= A proof let a be set; assume a in rng b; then consider c be set such that A16: c in dom b & b.c = a by FUNCT_1:def 5; A17: a in coprod(O.c,X) by A15,A16; dom O = Seg len O by FINSEQ_1:def 3; then A18: O.c in rng O & rng O c= the carrier of S by A15,A16,FINSEQ_1:def 4,FUNCT_1:def 5; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).(O.c) in rng coprod(X) by A18,FUNCT_1:def 5; then coprod(O.c,X) in rng coprod(X) by A18,Def3; then a in union rng coprod(X) by A17,TARSKI:def 4; then a in Union coprod(X) by PROB_1:def 3; hence thesis by XBOOLE_0:def 2; end; then reconsider b as FinSequence of A by FINSEQ_1:def 4; reconsider b as Element of A* by FINSEQ_1:def 11; A19: len b = len O by A15,FINSEQ_1:def 3; now let c be set; assume A20: c in dom b; then A21: P[c,b.c] by A15; dom O = Seg len O by FINSEQ_1:def 3; then A22: O.c in rng O & rng O c= the carrier of S by A15,A20,FINSEQ_1:def 4,FUNCT_1:def 5; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).(O.c) in rng coprod(X) by A22,FUNCT_1:def 5; then coprod(O.c,X) in rng coprod(X) by A22,Def3; then b.c in union rng coprod(X) by A21,TARSKI:def 4; then b.c in Union coprod(X) by PROB_1:def 3; hence b.c in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.c holds the_result_sort_of o1 = O.c by A1,XBOOLE_0:3; assume b.c in Union (coprod X); thus b.c in coprod(O.c,X) by A15,A20; end; then [xa,b] in REL(X) by A19,Th5; then xa ==> b by A2,LANG1:def 1; then xa in { t where t is Symbol of D: ex n be FinSequence st t ==> n}; hence thesis by A10,A11,LANG1:def 3; end; thus Terminals D c= Union (coprod X) proof let x be set; assume A23: x in Terminals D; then A24: x in A by A2,A3,XBOOLE_0:def 2; not x in [:the OperSymbols of S,{the carrier of S}:] by A3,A8,A23,XBOOLE_0:3; hence thesis by A24,XBOOLE_0:def 2; end; let x be set; assume A25: x in Union (coprod X); then x in A by XBOOLE_0:def 2; then x in Terminals D or x in NonTerminals D by A2,A3,XBOOLE_0:def 2; hence thesis by A1,A4,A25,XBOOLE_0:3; end; reserve x for set; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; cluster DTConMSA(X) -> with_terminals with_nonterminals with_useful_nonterminals; coherence proof set D = DTConMSA(X), A = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)); A1: Union (coprod X) misses [:the OperSymbols of S,{the carrier of S}:] by Th4; A2: Terminals D = Union (coprod X) & NonTerminals D = [:the OperSymbols of S,{the carrier of S}:] by Th6; A3: D = DTConstrStr (# A , REL(X) #) by Def10; for nt being Symbol of D st nt in NonTerminals D ex p being FinSequence of TS(D) st nt ==> roots p proof let nt be Symbol of D; assume nt in NonTerminals D; then consider o being OperSymbol of S, x2 being Element of {the carrier of S} such that A4: nt = [o,x2] by A2,DOMAIN_1:9; A5: the carrier of S = x2 by TARSKI:def 1; set O = the_arity_of o; defpred P[set,set] means $2 in coprod(O.$1,X); A6: for a be set st a in Seg len O ex b be set st P[a,b] proof let a be set; assume a in Seg len O; then a in dom O by FINSEQ_1:def 3; then A7: O.a in rng O & rng O c= the carrier of S by FINSEQ_1:def 4,FUNCT_1:def 5; then X.(O.a) is non empty by PBOOLE:def 16; then consider x be set such that A8: x in X.(O.a) by XBOOLE_0:def 1; take y = [x,O.a]; thus y in coprod(O.a,X) by A7,A8,Def2; end; consider b be Function such that A9: dom b = Seg len O & for a be set st a in Seg len O holds P[a,b.a] from NonUniqFuncEx(A6); reconsider b as FinSequence by A9,FINSEQ_1:def 2; A10: rng b c= A proof let a be set; assume a in rng b; then consider c be set such that A11: c in dom b & b.c = a by FUNCT_1:def 5; A12: a in coprod (O.c,X) by A9,A11; dom O = Seg len O by FINSEQ_1:def 3; then A13: O.c in rng O & rng O c= the carrier of S by A9,A11,FINSEQ_1:def 4,FUNCT_1:def 5; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).(O.c) in rng coprod(X) by A13,FUNCT_1:def 5; then coprod(O.c,X) in rng coprod(X) by A13,Def3; then a in union rng coprod(X) by A12,TARSKI:def 4; then a in Union coprod(X) by PROB_1:def 3; hence thesis by XBOOLE_0:def 2; end; then reconsider b as FinSequence of A by FINSEQ_1:def 4; reconsider b as Element of A* by FINSEQ_1:def 11; A14: len b = len O by A9,FINSEQ_1:def 3; now let c be set; assume A15: c in dom b; then A16: P[c,b.c] by A9; dom O = Seg len O by FINSEQ_1:def 3; then A17: O.c in rng O & rng O c= the carrier of S by A9,A15,FINSEQ_1:def 4,FUNCT_1:def 5; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).(O.c) in rng coprod(X) by A17,FUNCT_1:def 5; then coprod(O.c,X) in rng coprod(X) by A17,Def3; then b.c in union rng coprod(X) by A16,TARSKI:def 4; then b.c in Union coprod(X) by PROB_1:def 3; hence b.c in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = b.c holds the_result_sort_of o1 = O.c by A1,XBOOLE_0:3; assume b.c in Union (coprod X); thus b.c in coprod(O.c,X) by A9,A15; end; then [nt,b] in REL(X) by A4,A5,A14,Th5; then A18: nt ==> b by A3,LANG1:def 1; deffunc F(set)=root-tree (b.$1); consider f be Function such that A19: dom f = dom b & for x st x in dom b holds f.x = F(x) from Lambda; reconsider f as FinSequence by A9,A19,FINSEQ_1:def 2; rng f c= TS(D) proof let x; assume x in rng f; then consider y be set such that A20: y in dom f & f.y = x by FUNCT_1:def 5; A21: x = root-tree(b.y) by A19,A20; b.y in rng b by A19,A20,FUNCT_1:def 5; then reconsider a = b.y as Symbol of D by A3,A10; A22: P[y,b.y] by A9,A19,A20; dom O = Seg len O by FINSEQ_1:def 3; then A23: O.y in rng O & rng O c= the carrier of S by A9,A19,A20,FINSEQ_1:def 4,FUNCT_1:def 5; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).(O.y) in rng coprod(X) by A23,FUNCT_1:def 5; then coprod(O.y,X) in rng coprod(X) by A23,Def3; then b.y in union rng coprod(X) by A22,TARSKI:def 4; then a in Terminals D by A2,PROB_1:def 3; hence thesis by A21,DTCONSTR:def 4; end; then reconsider f as FinSequence of TS(D) by FINSEQ_1:def 4; take f; A24: dom (roots f) = dom f by DTCONSTR:def 1; for x st x in dom b holds (roots f).x = b.x proof let x; assume A25: x in dom b; then A26: f.x = root-tree (b.x) by A19; reconsider i = x as Nat by A25; consider T be DecoratedTree such that A27: T = f.i & (roots f).i = T.{} by A19,A25,DTCONSTR:def 1; thus thesis by A26,A27,TREES_4:3; end; hence thesis by A18,A19,A24,FUNCT_1:9; end; hence thesis by A2,DTCONSTR:def 6,def 7,def 8; end; end; theorem Th7: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, t be set holds t in Terminals DTConMSA(X) iff ex s be SortSymbol of S, x be set st x in X.s & t = [x,s] proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, t be set; set D = DTConMSA(X); A1: Terminals D = Union (coprod X) by Th6 .= union rng (coprod X) by PROB_1:def 3; thus t in Terminals D implies ex s be SortSymbol of S, x be set st x in X.s & t = [x,s] proof assume t in Terminals D; then consider A be set such that A2: t in A & A in rng(coprod X) by A1,TARSKI:def 4; consider s be set such that A3: s in dom (coprod X) & (coprod X).s = A by A2,FUNCT_1:def 5; reconsider s as SortSymbol of S by A3,PBOOLE:def 3; take s; (coprod X).s = coprod(s,X) by Def3; then consider x be set such that A4: x in X.s & t = [x,s] by A2,A3,Def2; take x; thus thesis by A4; end; given s be SortSymbol of S, x be set such that A5: x in X.s & t = [x,s]; t in coprod(s,X) by A5,Def2; then A6: t in (coprod X).s by Def3; dom(coprod X) = the carrier of S by PBOOLE:def 3; then (coprod X).s in rng (coprod X) by FUNCT_1:def 5; hence thesis by A1,A6,TARSKI:def 4; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S; func Sym(o,X) ->Symbol of DTConMSA(X) equals :Def11: [o,the carrier of S]; coherence proof the carrier of S in {the carrier of S} by TARSKI:def 1; then [o,the carrier of S] in [:the OperSymbols of S,{the carrier of S}:] by ZFMISC_1:106; then [o,the carrier of S] in NonTerminals (DTConMSA X) by Th6; hence [o,the carrier of S] is Symbol of DTConMSA(X); end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S; func FreeSort(X,s) -> Subset of TS(DTConMSA(X)) equals :Def12: {a where a is Element of TS(DTConMSA(X)): (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s}; coherence proof set A = {a where a is Element of TS(DTConMSA(X)): (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s}; A c= TS(DTConMSA(X)) proof let x be set; assume x in A; then consider a be Element of TS(DTConMSA(X)) such that A1: x = a and (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s; thus thesis by A1; end; hence thesis; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S; cluster FreeSort(X,s) -> non empty; coherence proof set A = {a where a is Element of TS(DTConMSA(X)): (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s}; consider x be set such that A1: x in X.s by XBOOLE_0:def 1; set a = [x,s]; A2: a in coprod(s,X) by A1,Def2; A3: (Terminals (DTConMSA(X))) = Union (coprod X) by Th6; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).s in rng coprod(X) by FUNCT_1:def 5; then coprod(s,X) in rng coprod(X) by Def3; then a in union rng coprod(X) by A2,TARSKI:def 4; then A4: a in Terminals (DTConMSA X) by A3,PROB_1:def 3; then reconsider a as Symbol of DTConMSA(X); reconsider b = root-tree a as Element of TS(DTConMSA X) by A4,DTCONSTR:def 4; b in A by A1; hence thesis by Def12; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; func FreeSort(X) -> ManySortedSet of the carrier of S means :Def13: for s be SortSymbol of S holds it.s = FreeSort(X,s); existence proof deffunc F(Element of S)=FreeSort(X,$1); consider f be Function such that A1: dom f = the carrier of S & for d be Element of S holds f.d =F(d) from LambdaB; reconsider f as ManySortedSet of the carrier of S by A1,PBOOLE:def 3; take f; thus thesis by A1; end; uniqueness proof let A,B be ManySortedSet of the carrier of S; assume that A2: for s be SortSymbol of S holds A.s = FreeSort(X,s) and A3: for s be SortSymbol of S holds B.s = FreeSort(X,s); for i be set st i in the carrier of S holds A.i = B.i proof let i be set; assume i in the carrier of S; then reconsider s = i as SortSymbol of S; A.s = FreeSort(X,s) & B.s = FreeSort(X,s) by A2,A3; hence thesis; end; hence thesis by PBOOLE:3; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; cluster FreeSort(X) -> non-empty; coherence proof let i be set; assume i in the carrier of S; then reconsider s = i as SortSymbol of S; (FreeSort(X)).s = FreeSort(X,s) by Def13; hence thesis; end; end; theorem Th8: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S, x be set st x in ((FreeSort X)# * (the Arity of S)).o holds x is FinSequence of TS(DTConMSA(X)) proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S, x be set; assume A1: x in ((FreeSort X)# * (the Arity of S)).o; set D = DTConMSA(X), ar = the_arity_of o, cr = the carrier of S; (the Arity of S).o = ar by MSUALG_1:def 6; then x in product ((FreeSort X) * ar) by A1,Th1; then consider f be Function such that A2: x = f & dom f = dom ((FreeSort X) * ar) & for y be set st y in dom ((FreeSort X)* ar) holds f.y in ((FreeSort X) * ar).y by CARD_3:def 5; A3: rng ar c= cr by FINSEQ_1:def 4; dom ((FreeSort X)) = cr by PBOOLE:def 3; then A4: dom ((FreeSort X) * ar) = dom ar by A3,RELAT_1:46; dom ar = Seg len ar by FINSEQ_1:def 3; then reconsider f as FinSequence by A2,A4,FINSEQ_1:def 2; rng f c= TS D proof let a be set; assume a in rng f; then consider b be set such that A5: b in dom f & f.b = a by FUNCT_1:def 5; A6: a in ((FreeSort X) * ar).b by A2,A5; reconsider b as Nat by A5; ((FreeSort X) * ar).b = (FreeSort X).(ar.b) by A2,A5,FUNCT_1:22 .= (FreeSort X). (ar/.b) by A2,A4,A5,FINSEQ_4:def 4 .= FreeSort(X,ar/.b) by Def13 .= { s where s is Element of TS D: (ex x be set st x in X.(ar/.b) & s = root-tree [x,ar/.b]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = s.{} & the_result_sort_of o1=ar/.b} by Def12; then consider e be Element of TS D such that A7: a = e and (ex x be set st x in X.(ar/.b) & e = root-tree [x,(ar/.b)]) or ex o be OperSymbol of S st [o,the carrier of S] = e.{} & the_result_sort_of o=ar/.b by A6; thus thesis by A7; end; then reconsider f as FinSequence of TS(D) by FINSEQ_1:def 4; f = x by A2; hence thesis; end; theorem Th9: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S, p be FinSequence of TS(DTConMSA(X)) holds p in ((FreeSort X)# * (the Arity of S)).o iff dom p = dom (the_arity_of o) & for n be Nat st n in dom p holds p.n in FreeSort(X,(the_arity_of o)/.n) proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S, p be FinSequence of TS(DTConMSA(X)); set AR = the Arity of S, cr = the carrier of S, ar = the_arity_of o; thus p in ((FreeSort X)# * AR).o implies dom p = dom (the_arity_of o) & for n be Nat st n in dom p holds p.n in FreeSort(X,(the_arity_of o)/.n) proof assume A1: p in ((FreeSort X)# * (the Arity of S)).o; AR.o = ar by MSUALG_1:def 6; then p in product ((FreeSort X) * ar) by A1,Th1; then A2: dom p = dom ((FreeSort X) * ar) & for x be set st x in dom ((FreeSort X) * ar) holds p.x in ((FreeSort X) * ar).x by CARD_3:18; A3: rng ar c= cr by FINSEQ_1:def 4; A4: dom ((FreeSort X)) = cr by PBOOLE:def 3; then A5: dom ((FreeSort X) * ar) = dom ar by A3,RELAT_1:46; thus dom p = dom ar by A2,A3,A4,RELAT_1:46; let n be Nat; assume A6: n in dom p; then ((FreeSort X) * ar).n = (FreeSort X).(ar.n) by A2,FUNCT_1:22 .= (FreeSort X). (ar/.n) by A2,A5,A6,FINSEQ_4:def 4 .= FreeSort(X,ar/.n) by Def13; hence thesis by A2,A6; end; assume A7: dom p = dom (the_arity_of o) & for n be Nat st n in dom p holds p.n in FreeSort(X,(the_arity_of o)/.n); AR.o = ar by MSUALG_1:def 6; then A8: ((FreeSort X)# * AR).o = product ((FreeSort X) * ar) by Th1; A9: rng ar c= cr by FINSEQ_1:def 4; dom ((FreeSort X)) = cr by PBOOLE:def 3; then A10: dom p = dom ((FreeSort X) * ar) by A7,A9,RELAT_1:46; for x be set st x in dom((FreeSort X) * ar) holds p.x in ((FreeSort X) * ar).x proof let x be set; assume A11: x in dom ((FreeSort X) * ar); then reconsider n = x as Nat by A10; FreeSort(X,ar/.n) = (FreeSort X). (ar/.n) by Def13 .= (FreeSort X).(ar.n) by A7,A10,A11,FINSEQ_4:def 4 .= ((FreeSort X) * ar).x by A11,FUNCT_1:22; hence thesis by A7,A10,A11; end; hence thesis by A8,A10,CARD_3:18; end; theorem Th10: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S, p be FinSequence of TS(DTConMSA(X)) holds Sym(o,X) ==> roots p iff p in ((FreeSort X)# * (the Arity of S)).o proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S, p be FinSequence of TS(DTConMSA(X)); set D = DTConMSA(X), ar = the_arity_of o; A1: Union (coprod X) misses [:the OperSymbols of S,{the carrier of S}:] by Th4; A2: Sym(o,X) = [o,the carrier of S] by Def11; A3: D = DTConstrStr (# [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)), REL(X) #) & (Terminals (DTConMSA(X))) = Union (coprod X) & NonTerminals(DTConMSA(X)) = [:the OperSymbols of S,{the carrier of S}:] by Def10,Th6; thus Sym(o,X) ==> roots p implies p in ((FreeSort X)# * (the Arity of S)).o proof assume Sym(o,X) ==> roots p; then A4: [[o,the carrier of S],roots p] in REL(X) by A2,A3,LANG1:def 1; then reconsider r = roots p as Element of ([:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X))* by ZFMISC_1:106; A5: len r = len ar & for x be set st x in dom r holds (r.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = r.x holds the_result_sort_of o1 = ar.x) & (r.x in Union (coprod X) implies r.x in coprod(ar.x,X)) by A4,Th5; A6: dom p = dom r by DTCONSTR:def 1; A7: dom r = Seg len r & Seg len ar = dom ar by FINSEQ_1:def 3; for n be Nat st n in dom p holds p.n in FreeSort(X,ar/.n) proof let n be Nat; set s = ar/.n, A = {a where a is Element of TS D: (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s}; A8: A = FreeSort(X,s) by Def12; assume A9: n in dom p; then consider T be DecoratedTree such that A10: T = p.n & r.n = T.{} by DTCONSTR:def 1; A11: rng r c= [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X) by FINSEQ_1:def 4; A12: r.n in rng r by A6,A9,FUNCT_1:def 5; A13: rng p c= TS D by FINSEQ_1:def 4; p.n in rng p by A9,FUNCT_1:def 5; then reconsider T as Element of TS(D) by A10,A13; per cases by A11,A12,XBOOLE_0:def 2; suppose A14: r.n in [:the OperSymbols of S,{the carrier of S}:]; then consider o1 being OperSymbol of S, x2 being Element of {the carrier of S} such that A15: r.n = [o1,x2] by DOMAIN_1:9; A16: x2 = the carrier of S by TARSKI:def 1; then the_result_sort_of o1 = ar.n by A4,A6,A9,A14,A15,Th5 .= ar/.n by A5,A6,A7,A9,FINSEQ_4:def 4; then (ex x be set st x in X.s & T = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = T.{} & the_result_sort_of o = s by A10,A15,A16; hence thesis by A8,A10; suppose A17: r.n in Union (coprod X); then r.n in coprod(ar.n,X) by A4,A6,A9,Th5; then r.n in coprod(s,X) by A5,A6,A7,A9,FINSEQ_4:def 4; then consider a be set such that A18: a in X.s & r.n = [a,s] by Def2; reconsider t = r.n as Terminal of D by A17,Th6; T = root-tree t by A10,DTCONSTR:9; hence thesis by A8,A10,A18; end; hence thesis by A5,A6,A7,Th9; end; set r = roots p, OU = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X); assume A19: p in ((FreeSort X)# * (the Arity of S)).o; then A20: dom p = dom ar & for n be Nat st n in dom p holds p.n in FreeSort(X,ar/.n) by Th9; A21: dom p = dom r by DTCONSTR:def 1; A22: dom r = Seg len r & Seg len ar = dom ar by FINSEQ_1:def 3; rng r c= [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X) proof let x be set; assume x in rng r; then consider n be set such that A23: n in dom r & r.n = x by FUNCT_1:def 5; reconsider n as Nat by A23; set s = ar/.n, A = {a where a is Element of TS D: (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s}; A24: A = FreeSort(X,s) by Def12; p.n in FreeSort(X,s) by A19,A21,A23,Th9; then consider a be Element of TS D such that A25: a = p.n and A26: (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s by A24; consider T be DecoratedTree such that A27: T = p.n & r.n = T.{} by A21,A23,DTCONSTR:def 1; per cases by A26; suppose ex x be set st x in X.s & a = root-tree [x,s]; then consider y be set such that A28: y in X.s & a = root-tree [y,s]; A29: a.{} = [y,s] by A28,TREES_4:3; A30: [y,s] in coprod(s,X) by A28,Def2; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).s in rng coprod(X) by FUNCT_1:def 5; then coprod(s,X) in rng coprod(X) by Def3; then [y,s] in union rng coprod(X) by A30,TARSKI:def 4; then [y,s] in Union (coprod X) by PROB_1:def 3; hence thesis by A23,A25,A27,A29,XBOOLE_0:def 2; suppose ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s; then consider o1 be OperSymbol of S such that A31: [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s; the carrier of S in {the carrier of S} by TARSKI:def 1; then [o1,the carrier of S] in [:the OperSymbols of S,{the carrier of S} :] by ZFMISC_1:106; hence thesis by A23,A25,A27,A31,XBOOLE_0:def 2; end; then reconsider r as FinSequence of OU by FINSEQ_1:def 4; reconsider r as Element of OU* by FINSEQ_1:def 11; A32: len r = len ar by A20,A21,A22,FINSEQ_1:8; for x be set st x in dom r holds (r.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = r.x holds the_result_sort_of o1 = ar.x) & (r.x in Union (coprod X) implies r.x in coprod(ar.x,X)) proof let x be set; assume A33: x in dom r; then reconsider n = x as Nat; set s = ar/.n, A = {a where a is Element of TS D: (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s}; A34: A = FreeSort(X,s) by Def12; p.n in FreeSort(X,s) by A19,A21,A33,Th9; then consider a be Element of TS D such that A35: a = p.n and A36: (ex x be set st x in X.s & a = root-tree [x,s]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = s by A34; consider T be DecoratedTree such that A37: T = p.n & r.n = T.{} by A21,A33,DTCONSTR:def 1; A38: s = ar.n by A20,A21,A33,FINSEQ_4:def 4; thus r.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = r.x holds the_result_sort_of o1 = ar.x proof assume A39: r.x in [:the OperSymbols of S,{the carrier of S}:]; let o1 be OperSymbol of S; assume A40: [o1,the carrier of S] = r.x; now given y be set such that A41: y in X.s & a = root-tree [y,s]; A42: r.x = [y,s] by A35,A37,A41,TREES_4:3; A43: [y,s] in coprod(s,X) by A41,Def2; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).s in rng coprod(X) by FUNCT_1:def 5; then coprod(s,X) in rng coprod(X) by Def3; then r.x in union rng coprod(X) by A42,A43,TARSKI:def 4; then r.x in Union (coprod X) by PROB_1:def 3; hence contradiction by A1,A39,XBOOLE_0:3; end; then consider o2 be OperSymbol of S such that A44: [o2,the carrier of S] = a.{} & the_result_sort_of o2 = s by A36; thus thesis by A35,A37,A38,A40,A44,ZFMISC_1:33; end; assume A45: r.x in Union (coprod X); now given o1 be OperSymbol of S such that A46: [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s; the carrier of S in {the carrier of S} by TARSKI:def 1; then [o1,the carrier of S] in [:the OperSymbols of S,{the carrier of S}:] by ZFMISC_1:106; hence contradiction by A1,A35,A37,A45,A46,XBOOLE_0:3; end; then consider y be set such that A47: y in X.s & a = root-tree [y,s] by A36; r.x = [y,s] by A35,A37,A47,TREES_4:3; hence thesis by A38,A47,Def2; end; then [[o,the carrier of S],r] in REL X by A32,Th5; hence thesis by A2,A3,LANG1:def 1; end; canceled; theorem Th12: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S holds union rng (FreeSort X) = TS (DTConMSA(X)) proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; set D = DTConMSA(X); A1: dom (FreeSort X) = the carrier of S & dom (coprod X) = the carrier of S by PBOOLE:def 3; thus union rng (FreeSort X) c= TS D proof let x; assume x in union rng (FreeSort X); then consider A be set such that A2: x in A & A in rng (FreeSort X) by TARSKI:def 4; consider s be set such that A3: s in dom (FreeSort X) & (FreeSort X).s = A by A2,FUNCT_1:def 5; reconsider s as SortSymbol of S by A3,PBOOLE:def 3; A = FreeSort(X,s) by A3,Def13 .= {a where a is Element of TS(D): (ex x be set st x in X.s & a = root-tree [x,s]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s} by Def12; then consider a be Element of TS(D) such that A4: a = x and (ex x be set st x in X.s & a = root-tree [x,s]) or ex o1 be OperSymbol of S st [o1,the carrier of S]=a.{} & the_result_sort_of o1 = s by A2; thus thesis by A4; end; let x; assume x in TS D; then reconsider t = x as Element of TS(D); A5: rng t c= the carrier of D by TREES_2:def 9; {} in dom t by TREES_1:47; then A6: t.{} in rng t by FUNCT_1:def 5; A7: the carrier of D = (Terminals D) \/ (NonTerminals D) by LANG1:1; A8: Terminals D = Union (coprod X) & NonTerminals D = [:the OperSymbols of S,{the carrier of S}:] by Th6; per cases by A5,A6,A7,XBOOLE_0:def 2; suppose A9: t.{} in Terminals D; then reconsider a = t.{} as Terminal of D; A10: t = root-tree a by DTCONSTR:9; a in union rng(coprod X) by A8,A9,PROB_1:def 3; then consider A be set such that A11: a in A & A in rng(coprod X) by TARSKI:def 4; consider s be set such that A12: s in dom(coprod X) & (coprod X).s = A by A11,FUNCT_1:def 5; reconsider s as SortSymbol of S by A12,PBOOLE:def 3; A = coprod(s,X) by A12,Def3; then consider b be set such that A13: b in X.s & a = [b,s] by A11,Def2; t in {aa where aa is Element of TS(D): (ex x be set st x in X.s & aa = root-tree [x,s]) or ex o1 be OperSymbol of S st [o1,the carrier of S] =aa.{} & the_result_sort_of o1 = s} by A10,A13 ; then t in FreeSort(X,s) by Def12; then A14: t in (FreeSort X).s by Def13; (FreeSort X).s in rng (FreeSort X) by A1,FUNCT_1:def 5; hence thesis by A14,TARSKI:def 4; suppose t.{} in NonTerminals D; then reconsider a = t.{} as NonTerminal of D; consider o being OperSymbol of S, x2 being Element of {the carrier of S} such that A15: a = [o,x2] by A8,DOMAIN_1:9; A16: x2 = the carrier of S by TARSKI:def 1; set rs = the_result_sort_of o; t in {aa where aa is Element of TS(D): (ex x be set st x in X.rs & aa = root-tree [x,rs]) or ex o1 be OperSymbol of S st [o1,the carrier of S] =aa.{} & the_result_sort_of o1 = rs} by A15,A16; then t in FreeSort(X,rs) by Def12; then A17: t in (FreeSort X).rs by Def13; (FreeSort X).rs in rng (FreeSort X) by A1,FUNCT_1:def 5; hence thesis by A17,TARSKI:def 4; end; theorem Th13: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s1,s2 be SortSymbol of S st s1 <> s2 holds (FreeSort X).s1 misses (FreeSort X).s2 proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s1,s2 be SortSymbol of S; assume that A1: s1 <> s2 and A2: (FreeSort X).s1 /\ (FreeSort X).s2 <> {}; consider x such that A3: x in (FreeSort X).s1 /\ (FreeSort X).s2 by A2,XBOOLE_0:def 1; A4: x in (FreeSort X).s1 & x in (FreeSort X).s2 by A3,XBOOLE_0:def 3; A5: (FreeSort X).s1 = FreeSort(X,s1) & (FreeSort X).s2 = FreeSort(X,s2) by Def13; set D = DTConMSA(X), A1 = {a where a is Element of TS(D): (ex x be set st x in X.s1 & a = root-tree [x,s1]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s1}, A2 = {a where a is Element of TS(D): (ex x be set st x in X.s2 & a = root-tree [x,s2]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s2}; A6: A1 = (FreeSort X).s1 & A2 = (FreeSort X).s2 by A5,Def12; then consider a be Element of TS D such that A7: a = x and A8: (ex x1 be set st x1 in X.s1 & a = root-tree [x1,s1]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s1 by A4; consider b be Element of TS D such that A9: b = x and A10: (ex x2 be set st x2 in X.s2 & b = root-tree [x2,s2]) or ex o2 be OperSymbol of S st [o2,the carrier of S]=b.{} & the_result_sort_of o2 = s2 by A4,A6; per cases by A8; suppose ex x1 be set st x1 in X.s1 & a = root-tree [x1,s1]; then consider x1 be set such that A11: x1 in X.s1 & a = root-tree [x1,s1]; now per cases by A10; case ex x2 be set st x2 in X.s2 & b = root-tree [x2,s2]; then consider x2 be set such that A12: x2 in X.s2 & b = root-tree [x2,s2]; [x1,s1] = [x2,s2] by A7,A9,A11,A12,TREES_4:4; hence contradiction by A1,ZFMISC_1:33; case ex o2 be OperSymbol of S st [o2,the carrier of S]=b.{} & the_result_sort_of o2 = s2; then consider o2 be OperSymbol of S such that A13: [o2,the carrier of S] = b.{} & the_result_sort_of o2 = s2; [o2,the carrier of S] = [x1,s1] by A7,A9,A11,A13,TREES_4:3; then A14:the carrier of S = s1 by ZFMISC_1:33; for X be set holds not X in X; hence contradiction by A14; end; hence contradiction; suppose ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s1; then consider o1 be OperSymbol of S such that A15: [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s1; now per cases by A10; case ex x2 be set st x2 in X.s2 & b = root-tree [x2,s2]; then consider x2 be set such that A16: x2 in X.s2 & b = root-tree [x2,s2]; [o1,the carrier of S] = [x2,s2] by A7,A9,A15,A16,TREES_4:3; then A17: the carrier of S = s2 by ZFMISC_1:33; for X be set holds not X in X; hence contradiction by A17; case ex o2 be OperSymbol of S st [o2,the carrier of S]=b.{} & the_result_sort_of o2 = s2; then consider o2 be OperSymbol of S such that A18: [o2,the carrier of S] = b.{} & the_result_sort_of o2 = s2; thus contradiction by A1,A7,A9,A15,A18,ZFMISC_1:33; end; hence contradiction; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, o be OperSymbol of S; func DenOp(o,X) -> Function of ((FreeSort X)# * (the Arity of S)).o, ((FreeSort X) * (the ResultSort of S)).o means :Def14: for p be FinSequence of TS(DTConMSA(X)) st Sym(o,X) ==> roots p holds it.p = (Sym(o,X))-tree p; existence proof set AL = ((FreeSort X)# * (the Arity of S)).o, AX = ((FreeSort X) * (the ResultSort of S)).o, D = DTConMSA(X), O = the OperSymbols of S, rs = the_result_sort_of o, RS = the ResultSort of S; defpred P[set,set] means for p be FinSequence of TS D st p = $1 holds $2 = (Sym(o,X))-tree p; A1: for x be set st x in AL ex y be set st y in AX & P[x,y] proof let x be set; assume A2: x in AL; then reconsider p = x as FinSequence of TS(D) by Th8; take y = (Sym(o,X))-tree p; o in O; then o in dom ((FreeSort X) * RS) by PBOOLE:def 3; then A3: AX =(FreeSort X).(RS.o) by FUNCT_1:22 .= (FreeSort X).rs by MSUALG_1:def 7 .= FreeSort(X,rs) by Def13; set A = {a where a is Element of TS(D): (ex x be set st x in X.rs & a = root-tree [x,rs]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = rs}; A4: A = AX by A3,Def12; Sym(o,X) ==> roots p by A2,Th10; then reconsider a = (Sym(o,X))-tree p as Element of TS D by DTCONSTR:def 4 ; (ex q being DTree-yielding FinSequence st p = q & dom a = tree doms q) & a.{} = Sym(o,X) & for n be Nat st n < len p holds a|<*n*> = p.(n+1) by TREES_4:def 4; then consider q being DTree-yielding FinSequence such that A5: p = q & dom a = tree doms q & a.{} = Sym(o,X) & for n be Nat st n < len p holds a|<*n*> = p.(n+1); Sym(o,X) = [o,the carrier of S] by Def11; hence y in AX by A4,A5; thus P[x,y]; end; consider f be Function such that A6: dom f = AL & rng f c= AX & for x be set st x in AL holds P[x,f.x] from NonUniqBoundFuncEx(A1); reconsider g = f as Function of AL,rng f by A6,FUNCT_2:3; reconsider g as Function of AL,AX by A6,FUNCT_2:4; take g; let p be FinSequence of TS D; assume Sym(o,X) ==> roots p; then p in AL by Th10; hence thesis by A6; end; uniqueness proof set AL = ((FreeSort X)# * (the Arity of S)).o, AX = ((FreeSort X) * (the ResultSort of S)).o, D = DTConMSA(X); let f,g be Function of AL, AX; assume that A7: for p be FinSequence of TS D st Sym(o,X) ==> roots p holds f.p = (Sym(o,X))-tree p and A8: for p be FinSequence of TS D st Sym(o,X) ==> roots p holds g.p = (Sym(o,X))-tree p; A9: dom f = AL & dom g = AL by FUNCT_2:def 1; for x be set st x in AL holds f.x = g.x proof let x be set; assume A10: x in AL; then reconsider p = x as FinSequence of TS(D) by Th8; Sym(o,X) ==> roots p by A10,Th10; then f.p = (Sym(o,X))-tree p & g.p = (Sym(o,X))-tree p by A7,A8; hence thesis; end; hence thesis by A9,FUNCT_1:9; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; func FreeOper(X) -> ManySortedFunction of (FreeSort X)# * (the Arity of S), (FreeSort X) * (the ResultSort of S) means :Def15: for o be OperSymbol of S holds it.o = DenOp(o,X); existence proof set Y = the OperSymbols of S; defpred P[set,set] means for o be OperSymbol of S st $1 = o holds $2 = DenOp(o,X); A1: for x be set st x in Y ex y be set st P[x,y] proof let x be set; assume x in Y; then reconsider o = x as OperSymbol of S; take DenOp(o,X); thus thesis; end; consider f be Function such that A2: dom f = Y & for x be set st x in Y holds P[x,f.x] from NonUniqFuncEx(A1); reconsider f as ManySortedSet of Y by A2,PBOOLE:def 3; for x be set st x in dom f holds f.x is Function proof let x be set; assume x in dom f; then reconsider o = x as OperSymbol of S by A2; f.o = DenOp(o,X) by A2; hence thesis; end; then reconsider f as ManySortedFunction of Y by PRALG_1:def 15; for x be set st x in Y holds f.x is Function of ((FreeSort X)# * (the Arity of S)).x, ((FreeSort X) * (the ResultSort of S)).x proof let x be set; assume x in Y; then reconsider o = x as OperSymbol of S; f.o = DenOp(o,X) by A2; hence thesis; end; then reconsider f as ManySortedFunction of (FreeSort X)# * (the Arity of S), (FreeSort X) * (the ResultSort of S) by MSUALG_1:def 2; take f; let o be OperSymbol of S; thus thesis by A2; end; uniqueness proof let A,B be ManySortedFunction of (FreeSort X)# * (the Arity of S), (FreeSort X) * (the ResultSort of S); assume that A3: for o be OperSymbol of S holds A.o = DenOp(o,X) and A4: for o be OperSymbol of S holds B.o = DenOp(o,X); for i be set st i in the OperSymbols of S holds A.i = B.i proof let i be set; assume i in the OperSymbols of S; then reconsider s = i as OperSymbol of S; A.s = DenOp(s,X) & B.s = DenOp(s,X) by A3,A4; hence thesis; end; hence thesis by PBOOLE:3; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; func FreeMSA(X) -> MSAlgebra over S equals :Def16: MSAlgebra (# FreeSort(X), FreeOper(X) #); coherence; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; cluster FreeMSA(X) -> strict non-empty; coherence proof MSAlgebra (# FreeSort(X), FreeOper(X) #) = FreeMSA X by Def16; hence thesis by MSUALG_1:def 8; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S; func FreeGen(s,X) -> Subset of (FreeSort(X)).s means :Def17: for x be set holds x in it iff ex a be set st a in X.s & x = root-tree [a,s]; existence proof set D = DTConMSA(X); defpred P[set] means ex a be set st a in X.s & $1 = root-tree [a,s]; consider A be set such that A1: for x holds x in A iff x in (FreeSort(X)).s & P[x] from Separation; A c= (FreeSort(X)).s proof let x; assume x in A; hence thesis by A1; end; then reconsider A as Subset of (FreeSort(X)).s; for x holds x in A iff P[x] proof let x; thus x in A implies P[x] by A1; assume A2: P[x]; then consider a be set such that A3: a in X.s & x = root-tree [a,s]; A4: (FreeSort X).s = FreeSort(X,s) by Def13; set A = {aa where aa is Element of TS(D): (ex x be set st x in X.s & aa = root-tree [x,s]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = aa.{} & the_result_sort_of o1 = s}; A5: A = (FreeSort X).s by A4,Def12; set sa = [a,s]; A6: sa in coprod(s,X) by A3,Def2; A7: Terminals D = Union (coprod X) by Th6; dom coprod(X) = the carrier of S by PBOOLE:def 3; then (coprod(X)).s in rng coprod(X) by FUNCT_1:def 5; then coprod(s,X) in rng coprod(X) by Def3; then sa in union rng coprod(X) by A6,TARSKI:def 4; then A8: sa in Terminals D by A7,PROB_1:def 3; then reconsider sa as Symbol of D; reconsider b = root-tree sa as Element of TS(D) by A8,DTCONSTR:def 4; b in A & b = x by A3; hence thesis by A1,A2,A5; end; hence thesis; end; uniqueness proof let A,B be Subset of (FreeSort(X)).s; assume that A9: for x be set holds x in A iff ex a be set st a in X.s & x = root-tree [a,s] and A10: for x be set holds x in B iff ex a be set st a in X.s & x = root-tree [a,s]; thus A c= B proof let x be set; assume x in A; then ex a be set st a in X.s & x = root-tree [a,s] by A9; hence thesis by A10; end; let x be set; assume x in B; then ex a be set st a in X.s & x = root-tree [a,s] by A10; hence thesis by A9; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S; cluster FreeGen(s,X) -> non empty; coherence proof consider x such that A1: x in X.s by XBOOLE_0:def 1; ex a be set st a in X.s & root-tree [x,s] = root-tree [a,s] by A1; hence thesis by Def17; end; end; theorem Th14: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S holds FreeGen(s,X) = {root-tree t where t is Symbol of DTConMSA(X): t in Terminals DTConMSA(X) & t`2 = s} proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S; set D = DTConMSA(X), A = {root-tree t where t is Symbol of D : t in Terminals D & t`2 = s}; thus FreeGen(s,X) c= A proof let x be set; assume x in FreeGen(s,X); then consider a be set such that A1: a in X.s & x = root-tree [a,s] by Def17; A2: [a,s] in Terminals D by A1,Th7; then reconsider t = [a,s] as Symbol of D; t`2 = s by MCART_1:7; hence thesis by A1,A2; end; let x be set; assume x in A; then consider t be Symbol of D such that A3: x = root-tree t & t in Terminals D & t`2 = s; consider s1 be SortSymbol of S, a be set such that A4: a in X.s1 & t = [a,s1] by A3,Th7; s = s1 by A3,A4,MCART_1:7; hence thesis by A3,A4,Def17; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; func FreeGen(X) -> GeneratorSet of FreeMSA(X) means :Def18: for s be SortSymbol of S holds it.s = FreeGen(s,X); existence proof set FM = FreeMSA(X), D = DTConMSA(X); A1: FM = MSAlgebra (# FreeSort(X), FreeOper(X) #) by Def16; deffunc F(Element of S)=FreeGen($1,X); consider f be Function such that A2: dom f = the carrier of S & for s be Element of S holds f.s = F(s) from LambdaB; reconsider f as ManySortedSet of the carrier of S by A2,PBOOLE:def 3; f c= the Sorts of FM proof let x; assume x in the carrier of S; then reconsider s = x as SortSymbol of S; f.s = FreeGen(s,X) & FreeGen(s,X) c= (FreeSort X).s by A2; hence thesis by A1; end; then reconsider f as MSSubset of FM by MSUALG_2:def 1; the Sorts of GenMSAlg(f) = the Sorts of FM proof the Sorts of GenMSAlg(f) is MSSubset of FM by MSUALG_2:def 10; hence A3: the Sorts of GenMSAlg(f) c= the Sorts of FM by MSUALG_2:def 1; defpred P[set] means $1 in union rng (the Sorts of GenMSAlg(f)); A4: for s be Symbol of D st s in Terminals D holds P[root-tree s] proof let t be Symbol of D; assume t in Terminals D; then t in Union (coprod X) by Th6; then t in union rng(coprod X) by PROB_1:def 3; then consider A be set such that A5: t in A & A in rng (coprod X) by TARSKI:def 4; consider s be set such that A6: s in dom (coprod X) & (coprod X).s = A by A5,FUNCT_1:def 5; reconsider s as SortSymbol of S by A6,PBOOLE:def 3; A = coprod(s,X) by A6,Def3; then consider a be set such that A7: a in X.s & t = [a,s] by A5,Def2; f is MSSubset of GenMSAlg(f) by MSUALG_2:def 18; then f c= the Sorts of GenMSAlg(f) by MSUALG_2:def 1; then f.s c= (the Sorts of GenMSAlg(f)).s by PBOOLE:def 5; then A8: FreeGen(s,X) c= (the Sorts of GenMSAlg(f)).s by A2; A9: root-tree t in FreeGen(s,X) by A7,Def17; dom (the Sorts of GenMSAlg(f)) = the carrier of S by PBOOLE:def 3; then (the Sorts of GenMSAlg(f)).s in rng (the Sorts of GenMSAlg(f)) by FUNCT_1:def 5; hence thesis by A8,A9,TARSKI:def 4; end; A10: for nt being Symbol of D, ts being FinSequence of TS(D) st nt ==> roots ts & for t being DecoratedTree of the carrier of D st t in rng ts holds P[t] holds P[nt-tree ts] proof let nt be Symbol of D, ts be FinSequence of TS(D); assume A11: nt ==> roots ts & for t being DecoratedTree of the carrier of D st t in rng ts holds P[t]; set G = GenMSAlg(f), OU = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)); reconsider B = the Sorts of G as MSSubset of FM by MSUALG_2:def 10; set AR = the Arity of S, RS = the ResultSort of S, BH = B# * the Arity of S, O = the OperSymbols of S; A12: B is opers_closed by MSUALG_2:def 10; A13: [nt,roots ts] in the Rules of D by A11,LANG1:def 1; A14: D = DTConstrStr (# OU, REL(X)#) & Terminals D = Union (coprod X) by Def10,Th6; then A15: [nt,roots ts] in REL(X) by A11,LANG1:def 1; reconsider sy = nt as Element of OU by A14; reconsider rt = roots ts as Element of OU* by A13,A14,ZFMISC_1:106; [sy,rt] in REL(X) by A11,A14,LANG1:def 1; then sy in [:the OperSymbols of S,{the carrier of S}:] by Def9; then consider o being OperSymbol of S, x2 being Element of {the carrier of S} such that A16: sy = [o,x2] by DOMAIN_1:9; A17: x2 = the carrier of S by TARSKI:def 1; set ar = the_arity_of o, rs = the_result_sort_of o; B is_closed_on o by A12,MSUALG_2:def 7; then A18: rng ((Den(o,FM))|(BH.o)) c= (B * RS).o by MSUALG_2:def 6; A19: Sym(o,X) = [o,the carrier of S] & nt = [o,the carrier of S] by A16,Def11,TARSKI:def 1; A20: Den(o,FM) = (FreeOper X).o by A1,MSUALG_1:def 11 .= DenOp(o,X) by Def15; A21: dom (FreeSort X) = the carrier of S & o in O & dom B = the carrier of S & dom RS = O & rng RS c= the carrier of S & AR.o = ar & RS.o = rs by FUNCT_2:def 1,MSUALG_1:def 6,def 7,PBOOLE:def 3,RELSET_1:12; dom DenOp(o,X) = ((FreeSort X)# * AR).o by FUNCT_2:def 1; then A22: ts in dom DenOp(o,X) by A11,A19,Th10; A23: BH.o = product (B * ar) by A21,Th1; rng ar c= the carrier of S by FINSEQ_1:def 4; then A24: dom (B * ar) = dom ar by A21,RELAT_1:46; A25: dom (roots ts) = dom ts by DTCONSTR:def 1; A26: len rt = len ar & for x st x in dom rt holds (rt.x in [:the OperSymbols of S,{the carrier of S}:] implies for o1 be OperSymbol of S st [o1,the carrier of S] = rt.x holds the_result_sort_of o1 = ar.x) & (rt.x in Union (coprod X) implies rt.x in coprod(ar.x,X)) by A15,A16,A17,Th5; A27: Seg len rt = dom rt & Seg len ar = dom ar by FINSEQ_1:def 3; then A28: dom ts = dom ar by A13,A14,A16,A17,A25,Th5; for x st x in dom (B * ar) holds ts.x in (B * ar).x proof let x; assume A29: x in dom (B * ar); then reconsider n = x as Nat by A24; A30: rng ts c= TS D by FINSEQ_1:def 4; A31: ts.n in rng ts by A24,A25,A26,A27,A29,FUNCT_1:def 5; then reconsider T = ts.x as Element of TS(D) by A30; P[T] by A11,A31; then consider A be set such that A32: T in A & A in rng (the Sorts of G) by TARSKI:def 4; consider s be set such that A33: s in dom(the Sorts of G) & (the Sorts of G).s = A by A32,FUNCT_1:def 5; reconsider s as SortSymbol of S by A33,PBOOLE:def 3; A34: (B * ar).x = B.(ar.n) by A29,FUNCT_1:22 .= B.(ar/.n) by A24,A29,FINSEQ_4:def 4; set b = ar/.n, A1 = {a where a is Element of TS D: (ex x be set st x in X.b & a = root-tree [x,b]) or ex o be OperSymbol of S st [o,the carrier of S] = a.{} & the_result_sort_of o = b}; A35: A1 = FreeSort(X,b) by Def12 .= (FreeSort X).b by Def13; consider t be DecoratedTree such that A36: t = ts.n & rt.n = t.{} by A24,A25,A26,A27,A29,DTCONSTR:def 1; A37: rng rt c= [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod X) by FINSEQ_1:def 4; A38: rt.n in rng rt by A24,A26,A27,A29,FUNCT_1:def 5; A39: now per cases by A37,A38,XBOOLE_0:def 2; suppose A40: rt.n in [:the OperSymbols of S,{the carrier of S}:]; then consider o1 being OperSymbol of S, x2 being Element of {the carrier of S} such that A41: rt.n = [o1,x2] by DOMAIN_1:9; A42: x2 = the carrier of S by TARSKI:def 1; then the_result_sort_of o1 = ar.n by A13,A14,A16,A17,A24,A25,A28, A29,A40,A41,Th5 .= b by A24,A29,FINSEQ_4:def 4; hence T in (FreeSort X).b by A35,A36,A41,A42; suppose A43: rt.n in Union (coprod X); then rt.n in coprod(ar.n,X) by A13,A14,A16,A17,A24,A25,A28,A29,Th5 ; then rt.n in coprod(b,X) by A24,A29,FINSEQ_4:def 4; then consider a be set such that A44: a in X.b & rt.n = [a,b] by Def2; reconsider tt = rt.n as Terminal of D by A43,Th6; T = root-tree tt by A36,DTCONSTR:9; hence T in (FreeSort X).b by A35,A44; end; now assume b <> s; then A45: (FreeSort X).s misses (FreeSort X).b by Th13; (the Sorts of G).s c= (the Sorts of FM).s by A3,PBOOLE:def 5; hence contradiction by A1,A32,A33,A39,A45,XBOOLE_0:3; end; hence thesis by A32,A33,A34; end; then ts in BH.o by A23,A24,A25,A26,A27,CARD_3:18; then ts in (dom DenOp(o,X)) /\ (BH.o) by A22,XBOOLE_0:def 3; then A46: ts in dom (DenOp(o,X) | (BH.o)) by FUNCT_1:68; then (DenOp(o,X) | (BH.o)).ts = (DenOp(o,X)).ts by FUNCT_1:68 .= nt-tree ts by A11,A19,Def14; then A47: nt-tree ts in rng ((Den(o,FM))|(BH.o)) by A20,A46,FUNCT_1:def 5; dom (B * RS) = O by PBOOLE:def 3; then (B * RS).o = B.rs & B.rs in rng B by A21,FUNCT_1:22,def 5; hence thesis by A18,A47,TARSKI:def 4; end; A48: for t being DecoratedTree of the carrier of D st t in TS D holds P[t] from DTConstrInd(A4,A10); A49: union rng(the Sorts of FM) c= union rng (the Sorts of GenMSAlg(f)) proof let x; assume x in union rng(the Sorts of FM); then consider A be set such that A50: x in A & A in rng(the Sorts of FM) by TARSKI:def 4; consider s be set such that A51: s in dom (FreeSort X) & (FreeSort X).s = A by A1,A50,FUNCT_1:def 5; reconsider s as SortSymbol of S by A51,PBOOLE:def 3; set D = DTConMSA(X); A = FreeSort(X,s) by A51,Def13 .= {a where a is Element of TS(D): (ex x be set st x in X.s & a = root-tree [x,s]) or ex o1 be OperSymbol of S st [o1,the carrier of S] = a.{} & the_result_sort_of o1 = s} by Def12; then consider a be Element of TS(D) such that A52: a = x and (ex x be set st x in X.s & a = root-tree [x,s]) or ex o1 be OperSymbol of S st [o1,the carrier of S]=a.{} & the_result_sort_of o1 = s by A50; thus thesis by A48,A52; end; let x; assume x in the carrier of S; then reconsider s = x as SortSymbol of S; (the Sorts of FM).s c= (the Sorts of GenMSAlg(f)).s proof let a be set; assume A53: a in (the Sorts of FM).s; the carrier of S = dom (the Sorts of FM) by PBOOLE:def 3; then (the Sorts of FM).s in rng (the Sorts of FM) by FUNCT_1:def 5; then a in union rng (the Sorts of FM) by A53,TARSKI:def 4; then consider A be set such that A54: a in A & A in rng (the Sorts of GenMSAlg(f)) by A49,TARSKI:def 4; consider b be set such that A55: b in dom (the Sorts of GenMSAlg(f)) & (the Sorts of GenMSAlg(f)).b = A by A54,FUNCT_1:def 5; reconsider b as SortSymbol of S by A55,PBOOLE:def 3; now assume b <> s; then (FreeSort X).s misses (FreeSort X).b by Th13; then A56: (FreeSort X).s /\ (FreeSort X).b = {} by XBOOLE_0:def 7; (the Sorts of GenMSAlg(f)).b c= (the Sorts of FM).b by A3,PBOOLE:def 5; hence contradiction by A1,A53,A54,A55,A56,XBOOLE_0:def 3; end; hence thesis by A54,A55; end; hence thesis; end; then reconsider f as GeneratorSet of FM by Def4; take f; thus thesis by A2; end; uniqueness proof let A,B be GeneratorSet of FreeMSA(X); assume that A57: for s be SortSymbol of S holds A.s = FreeGen(s,X) and A58: for s be SortSymbol of S holds B.s = FreeGen(s,X); for i be set st i in the carrier of S holds A.i = B.i proof let i be set; assume i in the carrier of S; then reconsider s = i as SortSymbol of S; A.s = FreeGen(s,X) & B.s = FreeGen(s,X) by A57,A58; hence thesis; end; hence thesis by PBOOLE:3; end; end; theorem for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S holds FreeGen(X)is non-empty proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; let x; assume x in the carrier of S; then reconsider s = x as SortSymbol of S; (FreeGen(X)).s = FreeGen(s,X) by Def18; hence thesis; end; theorem for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S holds union rng FreeGen(X) = {root-tree t where t is Symbol of DTConMSA(X): t in Terminals DTConMSA(X)} proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; set D = DTConMSA(X), A = union rng FreeGen(X), B = {root-tree t where t is Symbol of D : t in Terminals D}; A1: dom FreeGen(X) = the carrier of S by PBOOLE:def 3; thus A c= B proof let x; assume x in A; then consider C be set such that A2: x in C & C in rng FreeGen(X) by TARSKI:def 4; consider s be set such that A3: s in dom FreeGen(X) & (FreeGen(X)).s = C by A2,FUNCT_1:def 5; reconsider s as SortSymbol of S by A3,PBOOLE:def 3; C = FreeGen(s,X) by A3,Def18 .= {root-tree t where t is Symbol of D : t in Terminals D & t`2 = s} by Th14; then consider t be Symbol of D such that A4: x = root-tree t & t in Terminals D & t`2 = s by A2; thus thesis by A4; end; let x; assume x in B; then consider t be Symbol of D such that A5: x = root-tree t & t in Terminals D; consider s be SortSymbol of S, a be set such that A6: a in X.s & t = [a,s] by A5,Th7; t`2 = s by A6,MCART_1:7; then x in {root-tree tt where tt is Symbol of D : tt in Terminals D & tt`2 = s} by A5; then x in FreeGen(s,X) by Th14; then A7: x in (FreeGen(X)).s by Def18; (FreeGen(X)).s in rng (FreeGen(X)) by A1,FUNCT_1:def 5; hence thesis by A7,TARSKI:def 4; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, s be SortSymbol of S; func Reverse(s,X) -> Function of FreeGen(s,X),X.s means :Def19: for t be Symbol of DTConMSA(X) st root-tree t in FreeGen(s,X) holds it.(root-tree t) = t`1; existence proof set A = FreeGen(s,X), D = DTConMSA(X); defpred P[set,set] means for t be Symbol of D st $1 = root-tree t holds $2 = t`1; A1: for x be set st x in A ex a be set st a in X.s & P[x,a] proof let x be set; assume x in A; then x in {root-tree t where t is Symbol of D: t in Terminals D & t`2 = s } by Th14; then consider t be Symbol of D such that A2: x = root-tree t & t in Terminals D & t`2 = s; consider s1 be SortSymbol of S, a be set such that A3: a in X.s1 & t = [a,s1] by A2,Th7; take a; thus a in X.s by A2,A3,MCART_1:7; let t1 be Symbol of D; assume x = root-tree t1; then t = t1 by A2,TREES_4:4; hence thesis by A3,MCART_1:7; end; consider f be Function such that A4: dom f = A & rng f c= X.s & for x be set st x in A holds P[x,f.x] from NonUniqBoundFuncEx(A1); reconsider f as Function of A,X.s by A4,FUNCT_2:4; take f; let t be Symbol of D; assume root-tree t in A; hence thesis by A4; end; uniqueness proof let A,B be Function of FreeGen(s,X),X.s;assume that A5: for t be Symbol of DTConMSA(X) st root-tree t in FreeGen(s,X) holds A.(root-tree t) = t`1 and A6: for t be Symbol of DTConMSA(X) st root-tree t in FreeGen(s,X) holds B.(root-tree t) = t`1; set D = DTConMSA(X), C = {root-tree t where t is Symbol of D : t in Terminals D & t`2 = s}; A7: FreeGen(s,X) = C by Th14; then A8: dom A = C & dom B = C by FUNCT_2:def 1; for i be set st i in C holds A.i = B.i proof let i be set; assume A9: i in C; then consider t be Symbol of D such that A10: i = root-tree t & t in Terminals D & t`2 = s; A.(root-tree t) = t`1 & B.(root-tree t) = t`1 by A5,A6,A7,A9,A10; hence thesis by A10; end; hence thesis by A8,FUNCT_1:9; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; func Reverse(X) -> ManySortedFunction of FreeGen(X),X means :Def20: for s be SortSymbol of S holds it.s = Reverse(s,X); existence proof set I = the carrier of S, FG = FreeGen(X); defpred P[set,set] means for s be SortSymbol of S st s = $1 holds $2 = Reverse(s,X); A1: for i be set st i in I ex u be set st P[i,u] proof let i be set; assume i in I; then reconsider s = i as SortSymbol of S; take Reverse(s,X); let s1 be SortSymbol of S; assume s1 = i; hence thesis; end; consider H be Function such that A2: dom H = I & for i be set st i in I holds P[i,H.i] from NonUniqFuncEx(A1); reconsider H as ManySortedSet of I by A2,PBOOLE:def 3; for x be set st x in dom H holds H.x is Function proof let i be set; assume i in dom H; then reconsider s = i as SortSymbol of S by A2; H.s = Reverse(s,X) by A2; hence thesis; end; then reconsider H as ManySortedFunction of I by PRALG_1:def 15; for i be set st i in I holds H.i is Function of FG.i,X.i proof let i be set; assume i in I; then reconsider s = i as SortSymbol of S; A3: (FreeGen X).s = FreeGen(s,X) by Def18; H.i = Reverse(s,X) by A2; hence thesis by A3; end; then reconsider H as ManySortedFunction of FG,X by MSUALG_1:def 2; take H; let s be SortSymbol of S; thus thesis by A2; end; uniqueness proof let A,B be ManySortedFunction of FreeGen(X),X;assume that A4: for s be SortSymbol of S holds A.s = Reverse(s,X) and A5: for s be SortSymbol of S holds B.s = Reverse(s,X); for i be set st i in the carrier of S holds A.i = B.i proof let i be set; assume i in the carrier of S; then reconsider s = i as SortSymbol of S; A.s = Reverse(s,X) & B.s = Reverse(s,X) by A4,A5; hence thesis; end; hence thesis by PBOOLE:3; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, A be non-empty ManySortedSet of the carrier of S, F be ManySortedFunction of FreeGen(X), A, t be Symbol of DTConMSA(X); assume A1: t in Terminals (DTConMSA(X)); func pi(F,A,t) -> Element of Union A means :Def21: for f be Function st f = F.(t`2) holds it = f.(root-tree t); existence proof set FG = FreeGen(X), D = DTConMSA(X); consider s be SortSymbol of S, x be set such that A2: x in X.s & t = [x,s] by A1,Th7; FG.s = FreeGen(s,X) by Def18; then A3: dom (F.s) = FreeGen(s,X) by FUNCT_2:def 1 .= {root-tree tt where tt is Symbol of D: tt in Terminals D & tt`2 = s} by Th14; t`2 = s by A2,MCART_1:7; then root-tree t in dom (F.s) by A1,A3; then A4: (F.s).(root-tree t) in rng (F.s) by FUNCT_1:def 5; A5: rng (F.s) c= A.s by RELSET_1:12; dom A = the carrier of S by PBOOLE:def 3; then A.s in rng A by FUNCT_1:def 5; then (F.s).(root-tree t) in union rng A by A4,A5,TARSKI:def 4; then reconsider eu = (F.s).(root-tree t) as Element of Union A by PROB_1:def 3; take eu; let f be Function; assume f = F.(t`2); hence thesis by A2,MCART_1:7; end; uniqueness proof let a,b be Element of Union A; assume that A6: for f be Function st f = F.(t`2) holds a = f.(root-tree t) and A7: for f be Function st f = F.(t`2) holds b = f.(root-tree t); consider s be SortSymbol of S, x be set such that A8: x in X.s & t = [x,s] by A1,Th7; reconsider f = F.s as Function; f = F.(t`2) by A8,MCART_1:7; then a = f.(root-tree t) & b = f.(root-tree t) by A6,A7; hence thesis; end; end; definition let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S, t be Symbol of DTConMSA(X); assume A1: ex p be FinSequence st t ==> p; func @(X,t) -> OperSymbol of S means :Def22: [it,the carrier of S] = t; existence proof set D = DTConMSA(X), OU = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)); consider p be FinSequence such that A2: t ==> p by A1; A3: [t,p] in the Rules of D by A2,LANG1:def 1; A4: D = DTConstrStr (# OU, REL(X) #) by Def10; then reconsider a = t as Element of OU; reconsider p as Element of OU* by A3,A4,ZFMISC_1:106; [a,p] in REL(X) by A2,A4,LANG1:def 1; then a in [:the OperSymbols of S,{the carrier of S}:] by Def9; then consider o being OperSymbol of S, x2 being Element of {the carrier of S} such that A5: a = [o,x2] by DOMAIN_1:9; take o; thus thesis by A5,TARSKI:def 1; end; uniqueness by ZFMISC_1:33; end; definition let S be non void non empty ManySortedSign, U0 be non-empty MSAlgebra over S, o be OperSymbol of S, p be FinSequence; assume A1: p in Args(o,U0); func pi(o,U0,p) -> Element of Union (the Sorts of U0) equals :Def23: Den(o,U0).p; coherence proof set F = Den(o,U0), S0 = the Sorts of U0, RS = the ResultSort of S, rs = the_result_sort_of o; A2: dom F = Args(o,U0) & rng F c= Result(o,U0) by FUNCT_2:def 1,RELSET_1:12; then A3: F.p in rng F by A1,FUNCT_1:def 5; dom S0 = the carrier of S & rng RS c= the carrier of S by PBOOLE:def 3,RELSET_1:12; then S0.rs in rng S0 by FUNCT_1:def 5; then F.p in union rng S0 by A2,A3,TARSKI:def 4; hence F.p is Element of Union S0 by PROB_1:def 3; end; end; theorem Th17: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S holds FreeGen(X) is free proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; set D = DTConMSA(X), FA = FreeMSA(X), FG = FreeGen(X); let U1 be non-empty MSAlgebra over S, F be ManySortedFunction of FG,the Sorts of U1; set SA =the Sorts of FA, AR = the Arity of S, S1 = the Sorts of U1, O = the OperSymbols of S, RS = the ResultSort of S, DU = Union (the Sorts of U1); A1: FA = MSAlgebra (# FreeSort(X), FreeOper(X) #) by Def16; deffunc TermVal(Symbol of D) = pi(F,the Sorts of U1,$1); deffunc NTermVal(Symbol of D, FinSequence, FinSequence) = pi(@(X,$1),U1,$3); consider G being Function of TS(D), DU such that A2: for t being Symbol of D st t in Terminals D holds G.(root-tree t) = TermVal(t) and A3: for nt be Symbol of D, ts be FinSequence of TS(D) st nt ==> roots ts holds G.(nt-tree ts) = NTermVal(nt,roots ts,G * ts) from DTConstrIndDef; deffunc F(set) = G | ((the Sorts of FA).$1); consider h be Function such that A4: dom h = the carrier of S & for s be set st s in the carrier of S holds h.s = F(s) from Lambda; reconsider h as ManySortedSet of the carrier of S by A4,PBOOLE:def 3; for s be set st s in dom h holds h.s is Function proof let s be set; assume s in dom h; then h.s = G | ((the Sorts of FA).s) by A4; hence thesis; end; then reconsider h as ManySortedFunction of the carrier of S by PRALG_1:def 15; defpred P[set] means for s be SortSymbol of S st $1 in (the Sorts of FA).s holds (h.s).$1 in (the Sorts of U1).s; A5: for t being Symbol of D st t in Terminals D holds P[root-tree t] proof let t be Symbol of D; assume A6: t in Terminals D; then consider s be SortSymbol of S, x be set such that A7: x in X.s & t = [x,s] by Th7; set E = {root-tree tt where tt is Symbol of D: tt in Terminals D & tt`2 = s}, a = root-tree t; A8: t`2 = s by A7,MCART_1:7; then A9: a in E by A6; A10: E = FreeGen(s,X) & FreeGen(s,X) c= (FreeSort X).s by Th14; reconsider f = F.s as Function of FG.s,S1.s; A11: FG.s = E by A10,Def18; A12: dom f = FG.s & rng f c= S1.s by FUNCT_2:def 1,RELSET_1:12; then A13: f.a in rng f by A9,A11,FUNCT_1:def 5; h.s = G | (SA.s) by A4; then A14: (h.s).a = G.a by A1,A9,A10,FUNCT_1:72 .= pi(F,S1,t) by A2,A6 .= f.a by A6,A8,Def21; let s1 be SortSymbol of S; assume A15: a in SA.s1; now assume A16: s <> s1; a in (FreeSort X).s /\ (FreeSort X).s1 by A1,A9,A10,A15,XBOOLE_0:def 3; then (FreeSort X).s meets (FreeSort X).s1 by XBOOLE_0:4; hence contradiction by A16,Th13; end; hence thesis by A12,A13,A14; end; A17: for nt being Symbol of D, ts being FinSequence of TS(D) st nt ==> roots ts & for t being DecoratedTree of the carrier of D st t in rng ts holds P[t] holds P[nt-tree ts] proof let nt be Symbol of D, ts be FinSequence of TS(D); assume A18: nt ==> roots ts & for t being DecoratedTree of the carrier of D st t in rng ts holds P[t]; set p = G * ts, o = @(X,nt), ar = the_arity_of o, rs = the_result_sort_of o, OU = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)), rt = roots ts; A19: o in O & ar = AR.o by MSUALG_1:def 6; A20: Args(o,U1) = (S1# * AR).o by MSUALG_1:def 9 .= product (S1 * ar) by A19,Th1; A21: dom p = dom ts & len p = len ts & for n be Nat st n in dom p holds p.n = G.(ts.n) by ALG_1:1; A22: dom rt = dom ts by DTCONSTR:def 1; A23: [o,the carrier of S] = nt by A18,Def22; A24: [o,the carrier of S] = Sym(o,X) by Def11; A25: rng ar c= the carrier of S & dom S1 = the carrier of S & dom SA = the carrier of S by FINSEQ_1:def 4,PBOOLE:def 3; then A26: dom(S1* ar) = dom ar & dom(SA* ar) = dom ar by RELAT_1:46; A27: [[o,the carrier of S],rt] in the Rules of D by A18,A23,LANG1:def 1; A28: D = DTConstrStr (# OU, REL(X) #) by Def10; then reconsider rt as Element of OU* by A27,ZFMISC_1:106; A29: len rt = len ar by A27,A28,Th5; A30: dom rt = Seg len rt & Seg len ar = dom ar by FINSEQ_1:def 3; then A31: dom p = dom (S1 * ar) by A21,A22,A26,A27,A28,Th5; for x st x in dom (S1 * ar) holds p.x in (S1 * ar).x proof let x; assume A32: x in dom (S1 * ar); then reconsider n = x as Nat by A26; A33: p.n = G.(ts.n) by A31,A32,ALG_1:1; A34: rng ts c= TS D by FINSEQ_1:def 4; A35: ts.n in rng ts by A22,A26,A29,A30,A32,FUNCT_1:def 5; then reconsider t = ts.n as Element of TS(D) by A34; ts in ((FreeSort X)# * AR).o by A18,A23,A24,Th10; then ts in product ((FreeSort X) * ar) by A19,Th1; then ts.x in ((FreeSort X) * ar).x by A1,A26,A32,CARD_3:18; then A36: ts.x in (FreeSort X).(ar.x) by A1,A26,A32,FUNCT_1:22; ar.x in rng ar by A26,A32,FUNCT_1:def 5; then reconsider s = ar.x as SortSymbol of S by A25; A37: (h.s).t in S1.s by A1,A18,A35,A36; A38: h.s = G | (SA.s) by A4; A39: dom G = TS D by FUNCT_2:def 1 .= union rng SA by A1,Th12; dom SA = the carrier of S by PBOOLE:def 3; then SA.s in rng SA by FUNCT_1:def 5; then SA.s c= dom G by A39,ZFMISC_1:92; then dom (h.s) = SA.s by A38,RELAT_1:91; then G.t in S1.s by A1,A36,A37,A38,FUNCT_1:70; hence thesis by A32,A33,FUNCT_1:22; end; then A40: p in Args(o,U1) by A20,A21,A22,A26,A29,A30,CARD_3:18; then A41: pi(o,U1,p) = Den(o,U1).p by Def23; set ppi = pi(o,U1,p); A42: dom Den(o,U1) = Args(o,U1) & rng Den(o,U1) c= Result(o,U1) by FUNCT_2:def 1,RELSET_1:12; then ppi in rng Den(o,U1) by A40,A41,FUNCT_1:def 5; then A43: ppi in Result(o,U1) by A42; dom S1 = the carrier of S & rng RS c= the carrier of S & dom SA = the carrier of S by PBOOLE:def 3,RELSET_1:12; then A44: dom (S1 *RS) = dom RS & dom RS = O & dom (SA * RS) = dom RS by FUNCT_2:def 1,RELAT_1:46; A45: Result(o,U1) = (S1 *RS).o by MSUALG_1:def 10 .= S1.(RS.o) by A44,FUNCT_1:22 .= S1.rs by MSUALG_1:def 7; A46: G.(nt-tree ts) = ppi by A3,A18; A47: (DenOp(o,X)).ts = nt-tree ts by A18,A23,A24,Def14; A48: dom (DenOp (o,X)) = ((FreeSort X)# * AR).o & rng (DenOp (o,X)) c= ((FreeSort X) * RS).o by FUNCT_2:def 1,RELSET_1:12; then ts in dom (DenOp(o,X)) by A18,A23,A24,Th10; then nt-tree ts in rng (DenOp(o,X)) by A47,FUNCT_1:def 5; then nt-tree ts in (SA * RS).o by A1,A48; then nt-tree ts in SA.(RS.o) by A44,FUNCT_1:22; then A49: nt-tree ts in SA.rs by MSUALG_1:def 7; then A50: ppi = (G | (SA.rs)).(nt-tree ts) by A46,FUNCT_1:72; let s be SortSymbol of S; assume A51: nt-tree ts in SA.s; now assume A52: rs <> s; (FreeSort X).rs meets (FreeSort X).s by A1,A49,A51,XBOOLE_0:3; hence contradiction by A52,Th13; end; hence thesis by A4,A43,A45,A50; end; A53: for t being DecoratedTree of the carrier of D st t in TS(D) holds P[t] from DTConstrInd(A5,A17); for s be set st s in the carrier of S holds h.s is Function of (the Sorts of FA).s, (the Sorts of U1).s proof let x be set; assume x in the carrier of S; then reconsider s = x as SortSymbol of S; A54: h.s = G | (SA.s) by A4; A55: dom G = TS D by FUNCT_2:def 1 .= union rng SA by A1,Th12; dom SA = the carrier of S by PBOOLE:def 3; then SA.s in rng SA by FUNCT_1:def 5; then A56: SA.s c= dom G by A55,ZFMISC_1:92; then A57: dom (h.s) = SA.s by A54,RELAT_1:91; rng (h.s) c= S1.s proof let a be set; assume a in rng (h.s); then consider T be set such that A58: T in dom (h.s) & (h.s).T = a by FUNCT_1:def 5; reconsider T as Element of TS(D) by A56,A57,A58,FUNCT_2:def 1; T in SA.s by A54,A56,A58,RELAT_1:91; hence thesis by A53,A58; end; hence thesis by A57,FUNCT_2:def 1,RELSET_1:11; end; then reconsider h as ManySortedFunction of FA,U1 by MSUALG_1:def 2; take h; thus h is_homomorphism FA,U1 proof let o be OperSymbol of S such that Args(o,FA) <> {}; let x be Element of Args(o,FA); set rs = the_result_sort_of o, DA = Den(o,FA), D1 = Den(o,U1), OU = [:the OperSymbols of S,{the carrier of S}:] \/ Union (coprod (X qua ManySortedSet of the carrier of S)), ar = the_arity_of o; A59: DA = (FreeOper(X)).o by A1,MSUALG_1:def 11 .= DenOp(o,X) by Def15; A60: Args(o,FA) = ((FreeSort X)# * AR).o by A1,MSUALG_1:def 9; then A61: x in ((FreeSort X)# * AR).o; reconsider p = x as FinSequence of TS(D) by A60,Th8; A62: Sym(o,X) ==> roots p by A60,Th10; then A63: DA.x = (Sym(o,X))-tree p by A59,Def14; A64: o in O & ar = AR.o & dom AR = O by FUNCT_2:def 1,MSUALG_1:def 6; A65: Sym(o,X) = [o,the carrier of S] & [@(X,Sym(o,X)),the carrier of S] = Sym(o,X) by A62,Def11,Def22; then A66: @(X,Sym(o,X)) = o by ZFMISC_1:33; rng RS c= the carrier of S & dom SA = the carrier of S by PBOOLE:def 3,RELSET_1:12; then A67: dom RS = O & dom (SA * RS) = dom RS by FUNCT_2:def 1,RELAT_1:46; A68: (DenOp(o,X)).p = (Sym(o,X))-tree p by A62,Def14; A69: dom (DenOp (o,X)) = ((FreeSort X)# * AR).o & rng (DenOp (o,X)) c= ((FreeSort X) * RS).o by FUNCT_2:def 1,RELSET_1:12; then (Sym(o,X))-tree p in rng (DenOp(o,X)) by A60,A68,FUNCT_1:def 5; then (Sym(o,X))-tree p in (SA * RS).o by A1,A69; then (Sym(o,X))-tree p in SA.(RS.o) by A67,FUNCT_1:22; then A70: (Sym(o,X))-tree p in SA.rs by MSUALG_1:def 7; A71: h.rs = G | (SA.rs) by A4; A72: dom G = TS D by FUNCT_2:def 1 .= union rng SA by A1,Th12; A73: dom (G *p) = dom p & len (G*p) = len p & for n be Nat st n in dom(G*p) holds (G*p).n = G.(p.n) by ALG_1:1; A74: dom (h#x) = dom ar & dom x = dom ar by MSUALG_3:6; for a be set st a in dom p holds (G*p).a = (h#x).a proof let a be set; assume A75: a in dom p; then reconsider n = a as Nat; A76: (G*p).n = G.(x.n) by A73,A75; A77: (h#x).n = (h.(ar/.n)).(x.n) by A75,MSUALG_3:def 8; A78: h.(ar/.n) = G | (SA.(ar/.n)) by A4; A79: p in product((FreeSort X) * ar) by A61,A64,Th1; rng ar c= the carrier of S & dom S1 = the carrier of S & dom SA = the carrier of S by FINSEQ_1:def 4,PBOOLE:def 3; then A80: dom(S1* ar) = dom ar & dom(SA* ar) = dom ar by RELAT_1:46; set rt = roots p; A81: dom rt = dom p by DTCONSTR:def 1; A82: [[o,the carrier of S],rt] in the Rules of D by A62,A65,LANG1:def 1; A83: D = DTConstrStr (# OU, REL(X) #) by Def10; then reconsider rt as Element of OU* by A82,ZFMISC_1:106; A84: len rt = len ar by A82,A83,Th5; A85: Seg len rt = dom rt & Seg len ar = dom ar by FINSEQ_1:def 3; then A86: p.n in ((FreeSort X) * ar).n by A1,A75,A79,A80,A81,A84,CARD_3:18 ; ((FreeSort X) * ar).n = SA.(ar.n) by A1,A75,A80,A81,A84,A85,FUNCT_1:22 .= SA.(ar/.n) by A75,A81,A84,A85,FINSEQ_4:def 4; hence thesis by A76,A77,A78,A86,FUNCT_1:72; end; then A87: G*p = h#x by A73,A74,FUNCT_1:9; dom SA = the carrier of S by PBOOLE:def 3; then SA.rs in rng SA by FUNCT_1:def 5; then SA.rs c= dom G by A72,ZFMISC_1:92; then dom (h.rs) = SA.rs by A71,RELAT_1:91; hence (h.rs).(DA.x) = G.((Sym(o,X))-tree p) by A63,A70,A71,FUNCT_1:70 .= pi(@(X,Sym(o,X)),U1,G*p) by A3,A62 .= D1.(h#x) by A66,A87,Def23; end; for x st x in the carrier of S holds (h || FG).x = F.x proof let x; assume x in the carrier of S; then reconsider s = x as SortSymbol of S; set hf = h || FG; A88: hf.s = (h.s) | (FG.s) by Def1; A89: dom (h.s) = SA.s by FUNCT_2:def 1; A90: FG.s = FreeGen(s,X) by Def18; A91: dom (hf.s) = FG.s by FUNCT_2:def 1; A92: dom (F.s) = FG.s by FUNCT_2:def 1; for a be set st a in FG.s holds (hf.s).a = (F.s).a proof let a be set; assume A93: a in FG.s; then a in {root-tree t where t is Symbol of D: t in Terminals D & t`2 = s } by A90,Th14; then consider t be Symbol of D such that A94: a = root-tree t & t in Terminals D & t`2 = s; A95: h.s = G | (SA.s) by A4; thus (hf.s).a = (h.s).a by A88,A91,A93,FUNCT_1:70 .= G.a by A1,A89,A90,A93,A95,FUNCT_1:70 .= pi(F,S1,t) by A2,A94 .= (F.s).a by A94,Def21; end; hence thesis by A91,A92,FUNCT_1:9; end; hence h || FG = F by PBOOLE:3; end; theorem Th18: for S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S holds FreeMSA(X) is free proof let S be non void non empty ManySortedSign, X be non-empty ManySortedSet of the carrier of S; take FreeGen(X); thus thesis by Th17; end; definition let S be non void non empty ManySortedSign; cluster free strict (non-empty MSAlgebra over S); existence proof consider U1 be non-empty MSAlgebra over S; set X = the Sorts of U1; take FreeMSA(X); thus thesis by Th18; end; end; definition let S be non void non empty ManySortedSign, U0 be free MSAlgebra over S; cluster free GeneratorSet of U0; existence by Def6; end; theorem Th19: for S be non void non empty ManySortedSign, U1 be non-empty MSAlgebra over S ex U0 be strict free (non-empty MSAlgebra over S), F be ManySortedFunction of U0,U1 st F is_epimorphism U0,U1 proof let S be non void non empty ManySortedSign, U1 be non-empty MSAlgebra over S; set S1 = the Sorts of U1, FA = FreeMSA(S1), FG = FreeGen(S1); A1: FG is free by Th17; set f = Reverse(S1); consider F be ManySortedFunction of FA,U1 such that A2: F is_homomorphism FA,U1 & F || FG = f by A1,Def5; reconsider fa = FA as strict free (non-empty MSAlgebra over S) by Th18; reconsider a = F as ManySortedFunction of fa,U1; take fa; take a; thus a is_homomorphism fa,U1 by A2; thus a is "onto" proof let s be set; assume s in the carrier of S; then reconsider s0 = s as SortSymbol of S; reconsider g = a.s as Function of (the Sorts of fa).s0, S1.s0 by MSUALG_1:def 2; A3: f.s0 = g | (FG.s0) by A2,Def1; then A4: rng (f.s0) c= rng g by FUNCT_1:76; thus rng (a.s) c= S1.s by A3,RELSET_1:12; let x be set; assume A5: x in S1.s; set D = DTConMSA(S1), t = [x,s0]; A6: t in Terminals D by A5,Th7; then reconsider t as Symbol of D; A7: f.s0 = Reverse(s0,S1) by Def20; then A8: dom (f.s0) = FreeGen(s0,S1) by FUNCT_2:def 1; t`2 = s0 by MCART_1:7; then root-tree t in {root-tree tt where tt is Symbol of D : tt in Terminals D & tt`2 = s0} by A6; then A9: root-tree t in FreeGen(s0,S1) by Th14; then A10: (f.s0).(root-tree t) in rng (f.s0) by A8,FUNCT_1:def 5; (f.s0).(root-tree t) = t`1 by A7,A9,Def19 .= x by MCART_1:7; hence thesis by A4,A10; end; end; theorem for S be non void non empty ManySortedSign, U1 be strict non-empty MSAlgebra over S ex U0 be strict free (non-empty MSAlgebra over S), F be ManySortedFunction of U0,U1 st F is_epimorphism U0,U1 & Image F = U1 proof let S be non void non empty ManySortedSign, U1 be strict non-empty MSAlgebra over S; consider U0 be strict free (non-empty MSAlgebra over S), F be ManySortedFunction of U0,U1 such that A1: F is_epimorphism U0,U1 by Th19; F is_homomorphism U0,U1 by A1,MSUALG_3:def 10; then Image F = U1 by A1,MSUALG_3:19; hence thesis by A1; end;