Copyright (c) 1989 Association of Mizar Users
environ vocabulary BINOP_1, FUNCT_1, ARYTM_1, RELAT_1, FINSEQ_1, BOOLE, RLVECT_1, ANPROJ_1, ORDINAL2, ARYTM; notation TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, ORDINAL1, ORDINAL2, NUMBERS, XCMPLX_0, XREAL_0, DOMAIN_1, RELAT_1, FUNCT_1, FUNCT_2, BINOP_1, REAL_1, FINSEQ_1, NAT_1, STRUCT_0; constructors DOMAIN_1, BINOP_1, REAL_1, FINSEQ_1, NAT_1, STRUCT_0, XREAL_0, MEMBERED, XBOOLE_0, ORDINAL2; clusters RELSET_1, FINSEQ_1, STRUCT_0, XREAL_0, SUBSET_1, NAT_1, MEMBERED, ZFMISC_1, XBOOLE_0, ORDINAL2, NUMBERS, ARYTM_3, XCMPLX_0; requirements REAL, NUMERALS, BOOLE, SUBSET, ARITHM; definitions FUNCT_1, TARSKI, STRUCT_0, XBOOLE_0; theorems AXIOMS, BINOP_1, FUNCT_1, NAT_1, REAL_1, TARSKI, RELAT_1, STRUCT_0, XBOOLE_0, XBOOLE_1, FINSEQ_1, XCMPLX_0, XCMPLX_1; schemes BINOP_1, FINSEQ_1, FUNCT_2, NAT_1; begin definition struct (ZeroStr) LoopStr (# carrier -> set, add -> BinOp of the carrier, Zero -> Element of the carrier #); end; definition struct (LoopStr) RLSStruct (# carrier -> set, Zero -> Element of the carrier, add -> BinOp of the carrier, Mult -> Function of [:REAL, the carrier:], the carrier #); end; definition cluster non empty RLSStruct; existence proof consider ZS being non empty set, O being Element of ZS, F being BinOp of ZS, G being Function of [:REAL,ZS:],ZS; take RLSStruct(#ZS,O,F,G#); thus the carrier of RLSStruct(#ZS,O,F,G#) is non empty; end; end; reserve V for non empty RLSStruct; reserve x,y,y1,y2 for set; definition let V be RLSStruct; mode VECTOR of V is Element of V; end; definition let V be 1-sorted; let x; pred x in V means :Def1: x in the carrier of V; end; canceled 2; theorem for V being non empty 1-sorted, v being Element of V holds v in V proof let V be non empty 1-sorted, v be Element of V; thus thesis by Def1; end; :: :: Definitons of functions on the Elements of the carrier of :: Real Linear Space structure, i.e. zero element, addition of two :: elements, and multiplication of the element by a real number. :: definition let V be ZeroStr; func 0.V -> Element of V equals :Def2: the Zero of V; coherence; end; reserve v for VECTOR of V; reserve a,b for Real; definition cluster strict non empty LoopStr; existence proof set ZS = {0}; reconsider O = 0 as Element of ZS by TARSKI:def 1; consider F being BinOp of ZS; take LoopStr (# ZS,F,O #); thus LoopStr (# ZS,F,O #) is strict; thus the carrier of LoopStr (# ZS,F,O #) is non empty; end; end; definition let V be non empty LoopStr, v,w be Element of V; func v + w -> Element of V equals :Def3: (the add of V).[v,w]; coherence; end; definition let V; let v; let a; func a * v -> Element of V equals :Def4: (the Mult of V).[a,v]; coherence; end; :: :: Definitional theorems of zero element, addition, multiplication. :: canceled; theorem for V being non empty LoopStr, v,w being Element of V holds v + w = (the add of V).(v,w) proof let V be non empty LoopStr, v,w be Element of V; thus v + w = (the add of V).[v,w] by Def3 .= (the add of V).(v,w) by BINOP_1:def 1; end; definition let ZS be non empty set, O be Element of ZS, F be BinOp of ZS, G be Function of [:REAL,ZS:],ZS; cluster RLSStruct (# ZS,O,F,G #) -> non empty; coherence by STRUCT_0:def 1; end; Lm1: now take ZS = {0}; reconsider O = 0 as Element of ZS by TARSKI:def 1; take O; deffunc A((Element of ZS), Element of ZS) = O; consider F being BinOp of ZS such that A1: for x,y being Element of ZS holds F.(x,y) = A(x,y) from BinOpLambda; deffunc M((Element of REAL), Element of ZS) = O; consider G being Function of [:REAL,ZS:],ZS such that A2: for a being Element of REAL for x being Element of ZS holds G.[a,x qua set] = M(a,x) from Lambda2D; take F,G; set W = RLSStruct (# ZS,O,F,G #); thus for x,y being VECTOR of W holds x + y = y + x proof let x,y be VECTOR of W; x + y = F.[x,y] & y + x = F.[y,x] by Def3; then A3: x + y = F.(x,y) & y + x = F.(y,x) by BINOP_1:def 1; reconsider X = x, Y = y as Element of ZS; x + y = A(X,Y) & y + x = A(Y,X) by A1,A3; hence thesis; end; thus for x,y,z being VECTOR of W holds (x + y) + z = x + (y + z) proof let x,y,z be VECTOR of W; (x + y) + z = F.[x + y,z] & x + (y + z) = F.[x,y + z] by Def3; then A4: (x + y) + z = F.(x + y,z) & x + (y + z) = F.(x,y + z) by BINOP_1:def 1; reconsider X = x, Y = y, Z = z as Element of ZS; (x + y) + z = A(A(X,Y),Z) & x + (y + z) = A(X,A(Y,Z)) by A1,A4; hence thesis; end; thus for x being VECTOR of W holds x + 0.W = x proof let x be VECTOR of W; reconsider X = x as Element of ZS; x + 0.W = F.[x,0.W] by Def3 .= F.(x,0.W) by BINOP_1:def 1 .= A(X,O) by A1; hence thesis by TARSKI:def 1; end; thus for x being VECTOR of W ex y being VECTOR of W st x + y = 0.W proof let x be VECTOR of W; reconsider y = O as VECTOR of W; take y; thus x + y = F.[x,y] by Def3 .= F.(x,y) by BINOP_1:def 1 .= the Zero of W by A1 .= 0.W by Def2; end; thus for a for x,y being VECTOR of W holds a * (x + y) = a * x + a * y proof let a; let x,y be VECTOR of W; reconsider X = x, Y = y as Element of ZS; A5: a * (x + y) = G.[a,x + y] by Def4; a * x + a * y = F.[a * x,a * y] by Def3 .= F.(a * x,a * y) by BINOP_1:def 1 .= A(M(a,X),M(a,Y)) by A1; hence thesis by A2,A5; end; thus for a,b for x being VECTOR of W holds (a + b) * x = a * x + b * x proof let a,b; let x be VECTOR of W; set c = a + b; reconsider X = x as Element of ZS; A6: c * x = G.[c,x] by Def4 .= M(c,X) by A2; a * x + b * x = F.[a * x,b * x] by Def3 .= F.(a * x,b * x) by BINOP_1:def 1 .= A(M(a,X),M(b,X)) by A1; hence thesis by A6; end; thus for a,b for x being VECTOR of W holds (a * b) * x = a * (b * x) proof let a,b; let x be VECTOR of W; set c = a * b; reconsider X = x as Element of ZS; A7: c * x = G.[c,x] by Def4 .= M(c,X) by A2; a * (b * x) = G.[a,b * x] by Def4 .= M(a,M(b,X)) by A2; hence thesis by A7; end; thus for x being VECTOR of W holds 1 * x = x proof let x be VECTOR of W; reconsider X = x as Element of ZS; reconsider A' = 1 as Element of REAL; 1 * x = G.[1,x] by Def4 .= M(A',X) by A2; hence thesis by TARSKI:def 1; end; end; definition let IT be non empty LoopStr; attr IT is Abelian means :Def5: for v,w being Element of IT holds v + w = w + v; attr IT is add-associative means :Def6: for u,v,w being Element of IT holds (u + v) + w = u + (v + w); attr IT is right_zeroed means :Def7: for v being Element of IT holds v + 0.IT = v; attr IT is right_complementable means :Def8: for v being Element of IT ex w being Element of IT st v + w = 0.IT; end; definition let IT be non empty RLSStruct; attr IT is RealLinearSpace-like means :Def9: (for a for v,w being VECTOR of IT holds a * (v + w) = a * v + a * w) & (for a,b for v being VECTOR of IT holds (a + b) * v = a * v + b * v) & (for a,b for v being VECTOR of IT holds (a * b) * v = a * (b * v)) & (for v being VECTOR of IT holds 1 * v = v); end; definition cluster strict Abelian add-associative right_zeroed right_complementable (non empty LoopStr); existence proof set ZS = {0}; reconsider O = 0 as Element of ZS by TARSKI:def 1; deffunc A((Element of ZS), Element of ZS) = O; consider F being BinOp of ZS such that A1: for x,y being Element of ZS holds F.(x,y) = A(x,y) from BinOpLambda; reconsider W = LoopStr (# ZS,F,O #) as non empty LoopStr by STRUCT_0:def 1; take W; thus W is strict; thus for x,y being Element of W holds x + y = y + x proof let x,y be Element of W; x + y = F.[x,y] & y + x = F.[y,x] by Def3; then A2: x + y = F.(x,y) & y + x = F.(y,x) by BINOP_1:def 1; reconsider X = x, Y = y as Element of ZS; x + y = A(X,Y) & y + x = A(Y,X) by A1,A2; hence thesis; end; thus for x,y,z being Element of W holds (x + y) + z = x + (y + z) proof let x,y,z be Element of W; (x + y) + z = F.[x + y,z] & x + (y + z) = F.[x,y + z] by Def3; then A3: (x + y) + z = F.(x + y,z) & x + (y + z) = F.(x,y + z) by BINOP_1:def 1; reconsider X = x, Y = y, Z = z as Element of ZS; (x + y) + z = A(A(X,Y),Z) & x + (y + z) = A(X,A(Y,Z)) by A1,A3; hence thesis; end; thus for x being Element of W holds x + 0.W = x proof let x be Element of W; reconsider X = x as Element of ZS; x + 0.W = F.[x,0.W] by Def3 .= F.(x,0.W) by BINOP_1:def 1 .= A(X,O) by A1; hence thesis by TARSKI:def 1; end; let x be Element of W; reconsider y = O as Element of W; take y; thus x + y = F.[x,y] by Def3 .= F.(x,y) by BINOP_1:def 1 .= the Zero of W by A1 .= 0.W by Def2; end; end; definition cluster non empty strict Abelian add-associative right_zeroed right_complementable RealLinearSpace-like (non empty RLSStruct); existence proof consider ZS being non empty set, O being Element of ZS, F being BinOp of ZS, G being Function of [:REAL,ZS:],ZS such that A1: (for v,w being VECTOR of RLSStruct (# ZS,O,F,G #) holds v + w = w + v) & (for u,v,w being VECTOR of RLSStruct (# ZS,O,F,G #) holds (u + v) + w = u + (v + w)) & (for v being VECTOR of RLSStruct (# ZS,O,F,G #) holds v + 0.RLSStruct (# ZS,O,F,G #) = v) & (for v being VECTOR of RLSStruct (# ZS,O,F,G #) ex w being VECTOR of RLSStruct (# ZS,O,F,G #) st v + w = 0.RLSStruct (# ZS,O,F,G #)) & (for a for v,w being VECTOR of RLSStruct (# ZS,O,F,G #) holds a * (v + w) = a * v + a * w) & (for a,b for v being VECTOR of RLSStruct (# ZS,O,F,G #) holds (a + b) * v = a * v + b * v) & (for a,b for v being VECTOR of RLSStruct (# ZS,O,F,G #) holds (a * b) * v = a * (b * v)) & (for v being VECTOR of RLSStruct (# ZS,O,F,G #) holds 1 * v = v) by Lm1; take RLSStruct (# ZS,O,F,G #); thus RLSStruct (# ZS,O,F,G #) is non empty; thus thesis by A1,Def5,Def6,Def7,Def8,Def9; end; end; definition mode RealLinearSpace is Abelian add-associative right_zeroed right_complementable RealLinearSpace-like (non empty RLSStruct); end; definition let V be Abelian (non empty LoopStr), v,w be Element of V; redefine func v + w; commutativity by Def5; end; canceled; theorem (for v,w being VECTOR of V holds v + w = w + v) & (for u,v,w being VECTOR of V holds (u + v) + w = u + (v + w)) & (for v being VECTOR of V holds v + 0.V = v) & (for v being VECTOR of V ex w being VECTOR of V st v + w = 0.V) & (for a for v,w being VECTOR of V holds a * (v + w) = a * v + a * w) & (for a,b for v being VECTOR of V holds (a + b) * v = a * v + b * v) & (for a,b for v being VECTOR of V holds (a * b) * v = a * (b * v)) & (for v being VECTOR of V holds 1 * v = v) implies V is RealLinearSpace by Def5,Def6,Def7,Def8,Def9; :: :: Axioms of real linear space. :: reserve V for RealLinearSpace; reserve v,w for VECTOR of V; Lm2: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V st v + w = 0.V holds w + v = 0.V proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v,w be Element of V; assume A1: v + w = 0.V; consider u being Element of V such that A2: w + u = 0.V by Def8; w + v = w + (v + (w + u)) by A2,Def7 .= w + (v + w + u) by Def6 .= w + (v + w) + u by Def6 .= w + u by A1,Def7; hence thesis by A2; end; canceled 2; theorem Th10: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds v + 0.V = v & 0.V + v = v proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v be Element of V; thus A1: v + 0.V = v by Def7; consider w being Element of V such that A2: v + w = 0.V by Def8; w + v = 0.V by A2,Lm2; hence 0.V + v = v by A1,A2,Def6; end; :: :: Definitions of reverse element to the vector and of :: subtraction of vectors. :: definition let V be non empty LoopStr; let v be Element of V; assume A1: V is add-associative right_zeroed right_complementable; func - v -> Element of V means :Def10: v + it = 0.V; existence by A1,Def8; uniqueness proof let v1,v2 be Element of V; assume that A2: v + v1 = 0.V and A3: v + v2 = 0.V; thus v1 = v1 + (v + v2) by A1,A3,Th10 .= (v1 + v) + v2 by A1,Def6 .= 0.V + v2 by A1,A2,Lm2 .= v2 by A1,Th10; end; end; Lm3: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,u being Element of V ex w being Element of V st v + w = u proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,u be Element of V; take w = (- v) + u; thus v + w = (v + (- v)) + u by Def6 .= 0.V + u by Def10 .= u by Th10; end; definition let V be non empty LoopStr; let v,w be Element of V; func v - w -> Element of V equals :Def11: v + (- w); correctness; end; :: :: Definitional theorems of reverse element and substraction. :: canceled 5; theorem Th16: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds v + -v = 0.V & -v + v = 0.V proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v be Element of V; thus v + -v = 0.V by Def10; hence -v + v = 0.V by Lm2; end; canceled 2; theorem Th19: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds v + w = 0.V implies v = - w proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,w be Element of V; assume v + w = 0.V; then w + v = 0.V by Lm2; hence thesis by Def10; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,u being Element of V ex w being Element of V st v + w = u by Lm3; theorem Th21: for V being add-associative right_zeroed right_complementable (non empty LoopStr), w,u,v1,v2 being Element of V st w + v1 = w + v2 or v1 + w = v2 + w holds v1 = v2 proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let w,u,v1,v2 be Element of V; A1: now assume that A2: w + v1 = w + v2; thus v1 = 0.V + v1 by Th10 .= -w + w + v1 by Th16 .= -w + (w + v1) by Def6 .= -w + w + v2 by A2,Def6 .= 0.V + v2 by Th16 .= v2 by Th10; end; now assume that A3: v1 + w = v2 + w; thus v1 = v1 + 0.V by Th10 .= v1 + (w + -w) by Th16 .= v1 + w + -w by Def6 .= v2 + (w + -w) by A3,Def6 .= v2 + 0.V by Th16 .= v2 by Th10; end; hence thesis by A1; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds v + w = v or w + v = v implies w = 0.V proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v,w be Element of V; assume v + w = v or w + v = v; then v + w = v + 0.V or w + v = 0.V + v by Th10; hence thesis by Th21; end; theorem Th23: a = 0 or v = 0.V implies a * v = 0.V proof assume A1: a = 0 or v = 0.V; now per cases by A1; suppose A2: a = 0; v + 0 * v = 1 * v + 0 * v by Def9 .= (1 + 0) * v by Def9 .= v by Def9 .= v + 0.V by Th10; hence a * v = 0.V by A2,Th21; suppose A3: v = 0.V; a * 0.V + a * 0.V = a * (0.V + 0.V) by Def9 .= a * 0.V by Th10 .= a * 0.V + 0.V by Th10; hence a * v = 0.V by A3,Th21; end; hence thesis; end; theorem Th24: a * v = 0.V implies a = 0 or v = 0.V proof assume that A1: a * v = 0.V and A2: a <> 0; thus v = 1 * v by Def9 .= (a" * a) * v by A2,XCMPLX_0:def 7 .= a" * 0.V by A1,Def9 .= 0.V by Th23; end; theorem Th25: for V being add-associative right_zeroed right_complementable (non empty LoopStr) holds - 0.V = 0.V proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); thus 0.V = 0.V + (- 0.V) by Def10 .= - 0.V by Th10; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds v - 0.V = v proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v be Element of V; thus v - 0.V = v + (- 0.V) by Def11 .= v + 0.V by Th25 .= v by Th10; end; theorem Th27: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds 0.V - v = - v proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v be Element of V; thus 0.V - v = 0.V + (- v) by Def11 .= - v by Th10; end; theorem Th28: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds v - v = 0.V proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v be Element of V; thus v - v = v + (- v) by Def11 .= 0.V by Def10; end; theorem Th29: - v = (- 1) * v proof v + (- 1) * v = 1 * v + (- 1) * v by Def9 .= (1 + (- 1)) * v by Def9 .= 0.V by Th23; hence (- v) = (- v) + (v + (- 1) * v) by Th10 .= ((- v) + v) + (- 1) * v by Def6 .= 0.V + (- 1) * v by Def10 .= (- 1) * v by Th10; end; theorem Th30: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds - (- v) = v proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v be Element of V; v + -v = 0.V by Def10; hence thesis by Th19; end; theorem Th31: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds - v = - w implies v = w proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,w be Element of V; assume - v = - w; hence v = - (- w) by Th30 .= w by Th30; end; canceled; theorem Th33: v = - v implies v = 0.V proof assume v = - v; then 0.V = v - (- v) by Th28 .= v + (- (- v)) by Def11 .= v + v by Th30 .= 1 * v + v by Def9 .= 1 * v + 1 * v by Def9 .= (1 + 1) * v by Def9 .= 2 * v; hence thesis by Th24; end; theorem v + v = 0.V implies v = 0.V proof assume v + v = 0.V; then v = - v by Def10; hence thesis by Th33; end; theorem Th35: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds v - w = 0.V implies v = w proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,w be Element of V; assume v - w = 0.V; then 0.V = v + (- w) by Def11; then - v = - w by Def10; hence thesis by Th31; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), u,v being Element of V ex w being Element of V st v - w = u proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let u,v be Element of V; consider w being Element of V such that A1: v + w = u by Lm3; take z = - w; thus v - z = v + (- (- w)) by Def11 .= u by A1,Th30; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), w,v1,v2 being Element of V st w - v1 = w - v2 holds v1 = v2 proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let w,v1,v2 be Element of V; assume A1: w - v1 = w - v2; w + (- v1) = w - v1 & w + (- v2) = w - v2 by Def11; then - v1 = - v2 by A1,Th21; hence thesis by Th31; end; theorem Th38: a * (- v) = (- a) * v proof thus a * (- v) = a * ((- 1) * v) by Th29 .= (a *(- 1)) * v by Def9 .= (- (a * 1)) * v by XCMPLX_1:175 .= (- a) * v; end; theorem Th39: a * (- v) = - (a * v) proof thus a * (- v) = (- (1 * a)) * v by Th38 .= ((- 1) * a) * v by XCMPLX_1:175 .= (- 1) * (a * v) by Def9 .= - (a * v) by Th29; end; theorem (- a) * (- v) = a * v proof thus (- a) * (- v) = (- (- a)) * v by Th38 .= a * v; end; Lm4: for V being add-associative right_zeroed right_complementable (non empty LoopStr), u,w being Element of V holds - (u + w) = -w + -u proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), u,w be Element of V; u + w + (-w + -u) = u + (w + (-w + -u)) by Def6 .= u + (w + -w + -u) by Def6 .= u + (0.V + -u) by Def10 .= u + -u by Th10 .= 0.V by Def10; hence -(u + w) = -w + -u by Def10; end; theorem Th41: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds v - (u + w) = (v - w) - u proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,u,w be Element of V; thus v - (u + w) = v + - (u + w) by Def11 .= v + (-w + -u) by Lm4 .= (v + (- w)) + (- u) by Def6 .= (v - w) + (- u) by Def11 .= (v - w) - u by Def11; end; theorem for V being add-associative (non empty LoopStr), v,u,w being Element of V holds (v + u) - w = v + (u - w) proof let V be add-associative (non empty LoopStr); let v,u,w be Element of V; thus (v + u) - w = (v + u) + - w by Def11 .= v + (u + - w) by Def6 .= v + (u - w) by Def11; end; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds v - (u - w) = (v -u) + w proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr); let v,u,w be Element of V; thus v - (u - w) = v - (u + - w) by Def11 .= (v - u) - - w by Th41 .= (v - u) + (- - w) by Def11 .= (v - u) + w by Th30; end; theorem Th44: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds - (v + w) = (- w) - v proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,w be Element of V; thus - (v + w) = 0.V - (v + w) by Th27 .= (0.V - w) - v by Th41 .= (- w) - v by Th27; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds - (v + w) = -w + -v by Lm4; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds (- v) - w = (- w) - v proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr); let v,w be Element of V; thus (- v) - w = - (w + v) by Th44 .= (- w) - v by Th44; end; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds - (v - w) = w + (- v) proof let V be add-associative right_zeroed right_complementable (non empty LoopStr); let v,w be Element of V; thus - (v - w) = - (v + (- w)) by Def11 .= --w + -v by Lm4 .= w + -v by Th30; end; theorem Th48: a * (v - w) = a * v - a * w proof thus a * (v - w) = a * (v + (- w)) by Def11 .= a * v + a * (- w) by Def9 .= a * v + (- (a * w)) by Th39 .= a * v - a * w by Def11; end; theorem Th49: (a - b) * v = a * v - b * v proof thus (a - b) * v = (a + (- b)) * v by XCMPLX_0:def 8 .= a * v + (- b) * v by Def9 .= a * v + b * (- v) by Th38 .= a * v + (- (b * v)) by Th39 .= a * v - b * v by Def11; end; theorem a <> 0 & a * v = a * w implies v = w proof assume that A1: a <> 0 and A2: a * v = a * w; 0.V = a * v - a * w by A2,Th28 .= a * (v - w) by Th48; then v - w = 0.V by A1,Th24; hence thesis by Th35; end; theorem v <> 0.V & a * v = b * v implies a = b proof assume that A1: v <> 0.V and A2: a * v = b * v; 0.V = a * v - b * v by A2,Th28 .= (a - b) * v by Th49; then a - b = 0 by A1,Th24; then (- b) + a = 0 by XCMPLX_0:def 8; then a = - (- b) by XCMPLX_0:def 6; hence thesis; end; :: :: Definition of the sum of the finite sequence of vectors. :: definition let V be non empty 1-sorted; let v,u be Element of V; redefine func <* v,u *> -> FinSequence of the carrier of V; coherence proof <* v,u *> = <* v *> ^ <* u *> by FINSEQ_1:def 9; hence thesis; end; end; definition let V be non empty 1-sorted; let v,u,w be Element of V; redefine func <* v,u,w *> -> FinSequence of the carrier of V; coherence proof <* v,u,w *> = <* v,u *> ^ <* w *> by FINSEQ_1:60; hence thesis; end; end; reserve V for non empty LoopStr; reserve F,G,H for FinSequence of the carrier of V; reserve f,f',g for Function of NAT, the carrier of V; reserve v,u for Element of V; reserve j,k,n for Nat; definition let V; let F; func Sum(F) -> Element of V means :Def12: ex f st it = f.(len F) & f.0 = 0.V & for j,v st j < len F & v = F.(j + 1) holds f.(j + 1) = f.j + v; existence proof defpred P[set] means for F st len F = $1 ex u st ex f st u = f.(len F) & f.0 = 0.V & for j,v st j < len F & v = F.(j + 1) holds f.(j + 1) = f.j + v; A1: P[0] proof now let F; assume A2: len F = 0; deffunc G(Nat)=0.V; consider f being Function of NAT qua non empty set, the carrier of V such that A3: for j being Element of NAT qua non empty set holds f.j = G(j) from LambdaD; take u = f.(len F); take f' = f; thus u = f'.(len F) & f'.0 = 0.V by A3; let j; thus for v st j < len F & v = F.(j + 1) holds f'.(j + 1) = f'.j + v by A2,NAT_1:18; end; hence thesis; end; A4: for n be Nat st P[n] holds P[n+1] proof now let n; assume A5: for F st len F = n ex u st ex f st u = f.(len F) & f.0 = 0.V & for j,v st j < len F & v = F.(j + 1) holds f.(j + 1) = f.j + v; let F; assume A6: len F = n + 1; reconsider G = F | Seg(n) as FinSequence of the carrier of V by FINSEQ_1:23; A7: n < n + 1 by NAT_1:38; then A8: len G = n by A6,FINSEQ_1:21; then consider u,f such that u = f.(len G) and A9: f.0 = 0.V and A10: for j,v st j < len G & v = G.(j + 1) holds f.(j + 1) = f.j + v by A5; dom F = Seg(n + 1) by A6,FINSEQ_1:def 3; then n + 1 in dom F by FINSEQ_1:6; then F.(n + 1) in rng F & rng F c= the carrier of V by FINSEQ_1:def 4,FUNCT_1:def 5; then reconsider u1 = F.(n + 1) as Element of V; defpred P[set,set] means for j st $1 = j holds (j < n + 1 implies $2 = f.$1) & (n + 1 <= j implies for u st u = F.(n + 1) holds $2 = f.(len G) + u); A11: for k being Element of NAT qua non empty set ex v being Element of V st P[k,v] proof let k be Element of NAT qua non empty set; reconsider i = k as Element of NAT; A12: now assume A13: i < n + 1; take v = f.k; let j such that A14: k = j; thus j < n + 1 implies v = f.k; thus n + 1 <= j implies for u st u = F.(n + 1) holds v = f.(len G) + u by A13,A14; end; now assume A15: n + 1 <= i; take v = f.(len G) + u1; let j; assume k = j; hence j < n + 1 implies v = f.k by A15; assume n + 1 <= j; let u2 be Element of V; assume u2 = F.(n + 1); hence v = f.(len G) + u2; end; hence thesis by A12; end; consider f' being Function of NAT qua non empty set, the carrier of V such that A16: for k being Element of NAT qua non empty set holds P[k,f'.k] from FuncExD(A11); take z = f'.(n + 1); take f'' = f'; thus z = f''.(len F) by A6; 0 is Element of NAT & 0 < n + 1 by NAT_1:19; hence f''.0 = 0.V by A9,A16; let j,v; assume that A17: j < len F and A18: v = F.(j + 1); A19: now assume A20: j < n; then A21: j <= n & 1 <= 1 + j by NAT_1:29; 1 <= j + 1 & j + 1 <= n + 1 by A20,NAT_1:29,REAL_1:55; then j + 1 in Seg(n + 1) & j + 1 <= n by A20,FINSEQ_1:3,NAT_1:38; then j + 1 in dom F & j + 1 in Seg n by A6,A21,FINSEQ_1:3,def 3; then v = G.(j + 1) & j < len G by A6,A7,A18,A20,FINSEQ_1:21,FUNCT_1:72 ; then f.(j + 1) = f.j + v & j < n + 1 by A10,A20,NAT_1:38; then f.(j + 1) = f'.j + v & j + 1 < n + 1 by A16,A20,REAL_1:53; hence f''.(j + 1) = f''.j + v by A16; end; A22: now assume A23: j = n; then f''.(j + 1) = f.j + v by A8,A16,A18; hence f''.(j + 1) = f''.j + v by A7,A16,A23; end; j <= n by A6,A17,NAT_1:38; hence f''.(j + 1) = f''.j + v by A19,A22,REAL_1:def 5; end; hence thesis; end; for n holds P[n] from Ind(A1,A4); then consider u such that A24: ex f st u = f.(len F) & f.0 = 0.V & for j,v st j < len F & v = F.(j + 1) holds f.(j + 1) = f.j + v; thus thesis by A24; end; uniqueness proof let v1,v2 be Element of V; given f such that A25: v1 = f.(len F) and A26: f.0 = 0.V and A27: for j,v st j < len F & v = F.(j + 1) holds f.(j + 1) = f.j + v; given f' such that A28: v2 = f'.(len F) and A29: f'.0 = 0.V and A30: for j,v st j < len F & v = F.(j + 1) holds f'.(j + 1) = f'.j + v; defpred P[Nat] means $1 <= len F implies f.$1 = f'.$1; A31: P[0] by A26,A29; A32: for k st P[k] holds P[k+1] proof now let k; assume A33: k <= len F implies f.k = f'.k; assume A34: k + 1 <= len F; 1 <= k + 1 & dom F = Seg(len F) by FINSEQ_1:def 3,NAT_1:29; then k + 1 in dom F by A34,FINSEQ_1:3; then F.(k + 1) in rng F & rng F c= the carrier of V by FINSEQ_1:def 4,FUNCT_1:def 5; then reconsider u1 = F.(k + 1) as Element of V; k < len F by A34,NAT_1:38; then f.(k + 1) = f.k + u1 & f'.(k + 1) = f'.k + u1 & k <= len F by A27,A30; hence f.(k + 1) = f'.(k + 1) by A33; end; hence thesis; end; for k holds P[k] from Ind(A31,A32); hence v1 = v2 by A25,A28; end; end; Lm5: Sum(<*>(the carrier of V)) = 0.V proof set S = <*>(the carrier of V); ex f st Sum(S) = f.(len S) & f.0 = 0.V & for j,v st j < len S & v = S.(j + 1) holds f.(j + 1) = f.j + v by Def12; hence thesis by FINSEQ_1:25; end; Lm6: len F = 0 implies Sum(F) = 0.V proof assume len F = 0; then F = <*>(the carrier of V) by FINSEQ_1:32; hence thesis by Lm5; end; canceled 2; theorem Th54: k in Seg n & len F = n implies F.k is Element of V proof assume k in Seg n & len F = n; then k in dom F by FINSEQ_1:def 3; then F.k in rng F & rng F c= the carrier of V by FINSEQ_1:def 4,FUNCT_1:def 5; hence thesis; end; theorem Th55: len F = len G + 1 & G = F | (dom G) & v = F.(len F) implies Sum(F) = Sum(G) + v proof assume that A1: len F = len G + 1 and A2: G = F | (dom G) and A3: v = F.(len F); consider f such that A4: Sum(F) = f.(len F) and A5: f.0 = 0.V and A6: for j,v st j < len F & v = F.(j + 1) holds f.(j + 1) = f.j + v by Def12; consider g such that A7: Sum(G) = g.(len G) and A8: g.0 = 0.V and A9: for j,v st j < len G & v = G.(j + 1) holds g.(j + 1) = g.j + v by Def12; defpred P[Nat] means for H holds len H = $1 & H = F | (Seg $1) & len H <= len G implies f.(len H) = g.(len H); A10: P[0] by A5,A8; A11: for k st P[k] holds P[k+1] proof now let k; assume A12: for H st len H = k & H = F | (Seg k) & len H <= len G holds f.(len H) = g.(len H); let H; assume that A13: len H = k + 1 and A14: H = F | (Seg (k + 1)) and A15: len H <= len G; reconsider p = H | (Seg k) as FinSequence of the carrier of V by FINSEQ_1:23; 1 <= k + 1 & k + 1 <= len F by A1,A13,A15,NAT_1:37; then k + 1 in Seg(len F) by FINSEQ_1:3; then reconsider v = F.(k + 1) as Element of V by Th54; A16: k <= len H by A13,NAT_1:37; then A17: len p = k by FINSEQ_1:21; Seg k c= Seg(k + 1) by A13,A16,FINSEQ_1:7; then A18: p = F | (Seg k) by A14,FUNCT_1:82; A19: len p <= len G by A15,A16,A17,AXIOMS:22; k <= len G & len G < len F by A1,A15,A16,AXIOMS:22,REAL_1:69; then A20: k < len F by AXIOMS:22; 1 <= k + 1 & k + 1 <= len G by A13,A15,NAT_1:37; then k + 1 in Seg(len G) by FINSEQ_1:3; then k + 1 in dom G by FINSEQ_1:def 3; then A21: v = G.(k + 1) by A2,FUNCT_1:70; k < k + 1 by REAL_1:69; then k < len G by A13,A15,AXIOMS:22; then f.(k + 1) = f.k + v & g.(k + 1) = g.k + v by A6,A9,A20,A21; hence f.(len H) = g.(len H) by A12,A13,A17,A18,A19; end; hence thesis; end; A22: dom G = Seg len G by FINSEQ_1:def 3; for k holds P[k] from Ind(A10,A11); then A23: f.(len G) = g.(len G) by A2,A22; len G < len F by A1,REAL_1:69; hence thesis by A1,A3,A4,A6,A7,A23; end; reserve V for RealLinearSpace; reserve v for VECTOR of V; reserve F,G,H,I for FinSequence of the carrier of V; theorem len F = len G & (for k,v st k in dom F & v = G.k holds F.k = a * v) implies Sum(F) = a * Sum(G) proof defpred P[set] means for H,I st len H = len I & len H = $1 & (for k,v st k in Seg len H & v = I.k holds H.k = a * v) holds Sum(H) = a * Sum(I); A1: P[0] proof now let H,I; assume that A2: len H = len I & len H = 0 and for k,v st k in Seg len H & v = I.k holds H.k = a * v; Sum(H) = 0.V & Sum(I) = 0.V by A2,Lm6; hence Sum(H) = a * Sum(I) by Th23; end; hence thesis; end; A3: for n st P[n] holds P[n+1] proof now let n; assume A4: for H,I st len H = len I & len H = n & for k,v st k in Seg len H & v = I.k holds H.k = a * v holds Sum(H) = a * Sum(I); let H,I; assume that A5: len H = len I and A6: len H = n + 1 and A7: for k,v st k in Seg len H & v = I.k holds H.k = a * v; reconsider p = H | (Seg n),q = I | (Seg n) as FinSequence of the carrier of V by FINSEQ_1:23; A8: n <= n + 1 by NAT_1:37; then A9: len p = n & len q = n by A5,A6,FINSEQ_1:21; A10: now let k,v; assume that A11: k in Seg len p and A12: v = q.k; len p <= len H by A6,A8,FINSEQ_1:21; then A13: Seg len p c= Seg len H by FINSEQ_1:7; dom q = Seg n by A5,A6,A8,FINSEQ_1:21; then I.k = q.k by A9,A11,FUNCT_1:70; then A14: H.k = a * v by A7,A11,A12,A13; dom p = Seg n by A6,A8,FINSEQ_1:21; hence p.k = a * v by A9,A11,A14,FUNCT_1:70; end; A15: n + 1 in Seg(n + 1) by FINSEQ_1:6; then reconsider v1 = H.(n + 1),v2 = I.(n + 1) as VECTOR of V by A5,A6,Th54; A16: v1 = a * v2 by A6,A7,A15; A17: dom q = Seg len q by FINSEQ_1:def 3; dom p = Seg len p by FINSEQ_1:def 3; hence Sum(H) = Sum(p) + v1 by A6,A9,Th55 .= a * Sum(q) + a * v2 by A4,A9,A10,A16 .= a * (Sum(q) + v2) by Def9 .= a * Sum(I) by A5,A6,A9,A17,Th55; end; hence thesis; end; A18: dom F = Seg len F by FINSEQ_1:def 3; for n holds P[n] from Ind(A1,A3); hence thesis by A18; end; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), F,G being FinSequence of the carrier of V st len F = len G & (for k for v being Element of V st k in dom F & v = G.k holds F.k = - v) holds Sum(F) = - Sum(G) proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), F,G be FinSequence of the carrier of V; defpred P[set] means for H,I being FinSequence of the carrier of V st len H = len I & len H = $1 & (for k for v being Element of V st k in Seg len H & v = I.k holds H.k = - v) holds Sum(H) = - Sum(I); A1: P[0] proof now let H,I be FinSequence of the carrier of V; assume that A2: len H = len I & len H = 0 and for k for v being Element of V st k in Seg len H & v = I.k holds H.k = - v; Sum(H) = 0.V & Sum(I) = 0.V by A2,Lm6; hence Sum(H) = - Sum(I) by Th25; end; hence thesis; end; A3: for n st P[n] holds P[n+1] proof now let n; assume A4: for H,I being FinSequence of the carrier of V st len H = len I & len H = n & for k for v being Element of V st k in Seg len H & v = I.k holds H.k = - v holds Sum(H) = - Sum(I); let H,I be FinSequence of the carrier of V; assume that A5: len H = len I and A6: len H = n + 1 and A7: for k for v being Element of V st k in Seg(len H) & v = I.k holds H.k = - v; reconsider p = H | (Seg n),q = I | (Seg n) as FinSequence of the carrier of V by FINSEQ_1:23; A8: n <= n + 1 by NAT_1:37; then A9: len p = n & len q = n by A5,A6,FINSEQ_1:21; A10: now let k; let v be Element of V; assume that A11: k in Seg(len p) and A12: v = q.k; len p <= len H by A6,A8,FINSEQ_1:21; then A13: Seg(len p) c= Seg(len H) by FINSEQ_1:7; dom q = Seg n by A5,A6,A8,FINSEQ_1:21; then I.k = q.k by A9,A11,FUNCT_1:70; then A14: H.k = - v by A7,A11,A12,A13; dom p = Seg n by A6,A8,FINSEQ_1:21; hence p.k = - v by A9,A11,A14,FUNCT_1:70; end; A15: n + 1 in Seg(n + 1) by FINSEQ_1:6; then reconsider v1 = H.(n + 1),v2 = I.(n + 1) as Element of V by A5,A6,Th54; A16: v1 = - v2 by A6,A7,A15; A17: dom q = Seg len q by FINSEQ_1:def 3; dom p = Seg len p by FINSEQ_1:def 3; hence Sum(H) = Sum(p) + v1 by A6,A9,Th55 .= - Sum(q) + - v2 by A4,A9,A10,A16 .= - (Sum(q) + v2) by Lm4 .= - Sum(I) by A5,A6,A9,A17,Th55; end; hence thesis; end; A18: dom F = Seg len F by FINSEQ_1:def 3; for n holds P[n] from Ind(A1,A3); hence thesis by A18; end; Lm7: for j being natural number holds j < 1 implies j = 0 proof let j be natural number; assume j < 1; then j < 0 + 1; then A1: j <= 0 by NAT_1:38; assume j <> 0; hence thesis by A1,NAT_1:18; end; theorem Th58: for V being add-associative right_zeroed (non empty LoopStr), F,G being FinSequence of the carrier of V holds Sum(F ^ G) = Sum(F) + Sum(G) proof let V be add-associative right_zeroed (non empty LoopStr), F,G be FinSequence of the carrier of V; defpred P[set] means for G be FinSequence of the carrier of V st len G = $1 holds Sum(F ^ G) = Sum(F) + Sum(G); A1: P[0] proof let G be FinSequence of the carrier of V; assume len G = 0; then G = <*>(the carrier of V) & G = {} by FINSEQ_1:25; then F ^ G = F & Sum(G) = 0.V by Lm5,FINSEQ_1:47; hence thesis by Def7; end; A2: for k st P[k] holds P[k+1] proof let k; assume A3: for G being FinSequence of the carrier of V st len G = k holds Sum(F ^ G) = Sum(F) + Sum(G); let H be FinSequence of the carrier of V; assume A4: len H = k + 1; reconsider p = H | (Seg k) as FinSequence of the carrier of V by FINSEQ_1:23; A5: dom H = Seg(k + 1) by A4,FINSEQ_1:def 3; then A6: k + 1 in dom H by FINSEQ_1:6; then H.(k + 1) in rng H & rng H c= the carrier of V by FINSEQ_1:def 4,FUNCT_1:def 5; then reconsider v = H.(k + 1) as Element of V; A7: k <= k + 1 by NAT_1:37; then A8: len p = k by A4,FINSEQ_1:21; then A9: dom H = Seg(len p + len<* v *>) by A5,FINSEQ_1:56; dom p = Seg k by A4,A7,FINSEQ_1:21; then A10: dom p c= dom H by A5,A7,FINSEQ_1:7; A11: now let n; assume n in dom p; then n in dom H & n in Seg k by A4,A7,A10,FINSEQ_1:21; hence p.n = H.n by FUNCT_1:72; end; now let n; assume n in dom<* v *>; then n in {1} by FINSEQ_1:4,55; then n = 1 by TARSKI:def 1; hence H.(len p + n) = <* v *>.n by A8,FINSEQ_1:def 8; end; then H = p ^ <* v *> by A9,A11,FINSEQ_1:def 7; then F ^ H = (F ^ p) ^ <* v *> by FINSEQ_1:45; then len(F ^ H) = len(F ^ p) + len<* v *> by FINSEQ_1:35; then A12: len(F ^ H) = len(F ^ p) + 1 by FINSEQ_1:56; A13: dom(F ^ p) = Seg len(F ^ p) by FINSEQ_1:def 3; A14: dom(F ^ H) = Seg len(F ^ H) by FINSEQ_1:def 3 .= Seg(len F + len H) by FINSEQ_1:35; A15: Seg(len(F ^ p)) = Seg(len F + len p) by FINSEQ_1:35; len F + len p <= len F + len H by A4,A7,A8,REAL_1:55; then Seg len(F ^ p) c= dom(F ^ H) by A14,A15,FINSEQ_1:7; then A16: dom(F ^ p) = dom(F ^ H) /\ Seg(len(F ^ p)) by A13,XBOOLE_1: 28; now let x be set; assume A17: x in dom(F ^ p); then reconsider n = x as Nat; A18: now assume n in dom F; then (F ^ p).n = F.n & (F ^ H).n = F.n by FINSEQ_1:def 7; hence (F ^ p).x = (F ^ H).x; end; now assume not n in dom F; then A19: not n in Seg(len F) by FINSEQ_1:def 3; A20: 1 <= n by A13,A17,FINSEQ_1:3; then len F <= n by A19,FINSEQ_1:3; then consider j such that A21: n = len F + j by NAT_1:28; A22: now assume not 1 <= j; then j = 0 by Lm7; hence contradiction by A19,A20,A21,FINSEQ_1:3; end; now assume not j <= k; then len F + k < n & n <= len F + len p by A13,A15,A17,A21,FINSEQ_1:3,REAL_1:53; hence contradiction by A4,A7,FINSEQ_1:21; end; then j in Seg k by A22,FINSEQ_1:3; then A23: j in dom p by A4,A7,FINSEQ_1:21; then (F ^ p).n = p.j & (F ^ H).n = H.j by A10,A21,FINSEQ_1:def 7; hence (F ^ p).x = (F ^ H).x by A11,A23; end; hence (F ^ p).x = (F ^ H).x by A18; end; then A24: F ^ p = (F ^ H) | (Seg len (F ^ p)) by A16,FUNCT_1:68 .= (F ^ H) | (dom (F ^ p)) by FINSEQ_1:def 3; A25: dom p = Seg len p by FINSEQ_1:def 3; v = (F ^ H).(len F + len H) by A4,A6,FINSEQ_1:def 7 .= (F ^ H).(len(F ^ H)) by FINSEQ_1:35; hence Sum(F ^ H) = Sum(F ^ p) + v by A12,A24,Th55 .= (Sum(F) + Sum(p)) + v by A3,A8 .= Sum(F) + (Sum(p) + v) by Def6 .= Sum(F) + Sum(H) by A4,A8,A25,Th55; end; for k holds P[k] from Ind(A1,A2); then len G = len G implies thesis; hence thesis; end; Lm8: for k, n being natural number holds k <> 0 implies n < n + k proof let k, n be natural number; assume A1: k <> 0; A2: now assume n = n + k; then n + 0 = n + k; hence contradiction by A1,XCMPLX_1:2; end; n <= n + k & n <= k + n by NAT_1:37; hence n < n + k by A2,REAL_1:def 5; end; Lm9: for k being natural number holds Seg k = Seg(k + 1) \ {k + 1} proof let k be natural number; A1: Seg(k + 1) = Seg k \/ {k + 1} by FINSEQ_1:11; Seg k misses {k + 1} proof assume not thesis; then A2: Seg k /\ {k + 1} <> {} by XBOOLE_0:def 7; consider x being Element of Seg k /\ {k + 1}; A3: x in Seg k by A2,XBOOLE_0:def 3; then reconsider x as Nat; x in {k + 1} by A2,XBOOLE_0:def 3; then x = k + 1 by TARSKI:def 1; then x <= k & k < x by A3,FINSEQ_1:3,REAL_1:69; hence thesis; end; hence thesis by A1,XBOOLE_1:88; end; reserve V for add-associative right_zeroed right_complementable (non empty LoopStr); reserve F for FinSequence of the carrier of V; reserve v,v1,v2,u,w for Element of V; reserve i,j,k,n for Nat; reserve p,q for FinSequence; Lm10: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds Sum<* v *> = v proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v be Element of V; set S = <* v *>; consider f being Function of NAT, the carrier of V such that A1: Sum(S) = f.(len S) and A2: f.0 = 0.V and A3: for j for v being Element of V st j < len S & v = S.(j + 1) holds f.(j + 1) = f.j + v by Def12; A4: len S = 1 by FINSEQ_1:56; 0 < 1; then consider j such that A5: j < len S by A4; A6: j = 0 by A4,A5,Lm7; S.(j + 1) = S.(0 + 1) by A4,A5,Lm7 .= v by FINSEQ_1:57; then f.1 = 0.V + v by A2,A3,A5,A6 .= v by Th10; hence thesis by A1,FINSEQ_1:56; end; Lm11: for k, n being natural number holds k < k + n iff 1 <= n proof let k, n be natural number; thus k < k + n implies 1 <= n proof assume A1: k < k + n; assume not 1 <= n; then n = 0 by Lm7; hence thesis by A1; end; assume 1 <= n; then 0 <> n; hence thesis by Lm8; end; Lm12: p = (p ^ q) | (dom p) proof A1: dom(p ^ q) = Seg(len p + len q) & len p <= len p + len q & dom p = Seg len p by FINSEQ_1:def 3,def 7,NAT_1:37; then A2: dom p = dom(p ^ q) /\ Seg len p by FINSEQ_1:9; for x st x in dom p holds p.x = (p ^ q).x by FINSEQ_1:def 7; hence thesis by A1,A2,FUNCT_1:68; end; Lm13: rng p = rng q & p is one-to-one & q is one-to-one implies len p = len q proof defpred P[FinSequence] means $1 is one-to-one implies for q st rng $1 = rng q & q is one-to-one holds len $1 = len q; A1: P[{}] proof now assume {} is one-to-one; let q; assume that A2: rng {} = rng q and q is one-to-one; rng q = {} by A2,FINSEQ_1:27; hence len {} = len q by FINSEQ_1:27; end; hence thesis; end; A3: for p,x st P[p] holds P[p^<*x*>] proof now let p,x; assume A4: p is one-to-one implies for q st rng p = rng q & q is one-to-one holds len p = len q; assume A5: p ^ <* x *> is one-to-one; let q; assume that A6: rng(p ^ <* x *>) = rng q and A7: q is one-to-one; A8: rng(p ^ <* x *>) = rng p \/ rng<* x *> by FINSEQ_1:44 .= rng p \/ {x} by FINSEQ_1:55; x in {x} by TARSKI:def 1; then x in rng q by A6,A8,XBOOLE_0:def 2; then consider y such that A9: y in dom q and A10: x = q.y by FUNCT_1:def 5; A11: y in Seg(len q) by A9,FINSEQ_1:def 3; reconsider y as Nat by A9; A12: 1 <= y by A11,FINSEQ_1:3; then consider k such that A13: 1 + k = y by NAT_1:28; A14: y <= len q by A11,FINSEQ_1:3; then consider n such that A15: y + n = len q by NAT_1:28; reconsider q1 = q | (Seg k) as FinSequence by FINSEQ_1:19; defpred P[Nat,set] means $2 = q.(y + $1); A16: for j,y1,y2 st j in Seg n & P[j,y1] & P[j,y2] holds y1 = y2; A17: for j st j in Seg n ex x st P[j,x]; consider q2 being FinSequence such that A18: dom q2 = Seg n and A19: for j st j in Seg n holds P[j,q2.j] from SeqEx(A16,A17); k <= y by A13,NAT_1:37; then A20: k <= len q by A14,AXIOMS:22; then A21: len q1 = k by FINSEQ_1:21; A22: rng(q1 ^ q2) = rng q \ {x} proof thus rng(q1 ^ q2) c= rng q \ {x} proof let z be set; assume z in rng(q1 ^ q2); then A23: z in rng q1 \/ rng q2 by FINSEQ_1:44; A24: now assume A25: z in rng q1; A26: rng q1 = q .: (Seg k) & q .: (Seg k) c= rng q by RELAT_1:144,148; consider y1 such that A27: y1 in dom q1 and A28: q1.y1 = z by A25,FUNCT_1:def 5; A29: q1.y1 = q.y1 by A27,FUNCT_1:70; A30: y1 in Seg(len q1) by A27,FINSEQ_1:def 3; reconsider y1 as Nat by A27; A31: y1 <= k & k < y by A13,A21,A30,FINSEQ_1:3,REAL_1:69; Seg k c= Seg(len q) by A20,FINSEQ_1:7; then dom q1 c= Seg(len q) by A20,FINSEQ_1:21; then dom q1 c= dom q by FINSEQ_1:def 3; then x <> z by A7,A9,A10,A27,A28,A29,A31,FUNCT_1:def 8; then not z in {x} by TARSKI:def 1; hence thesis by A25,A26,XBOOLE_0:def 4; end; now assume z in rng q2; then consider y1 such that A32: y1 in dom q2 and A33: q2.y1 = z by FUNCT_1:def 5; reconsider y1 as Nat by A32; A34: q2.y1 = q.(y + y1) by A18,A19,A32; A35: 1 <= y + y1 by A12,NAT_1:37; y1 <= n by A18,A32,FINSEQ_1:3; then y + y1 <= len q by A15,REAL_1:55; then y + y1 in Seg(len q) by A35,FINSEQ_1:3; then A36: y + y1 in dom q by FINSEQ_1:def 3; then A37: z in rng q by A33,A34,FUNCT_1:def 5; y1 <> 0 by A18,A32,FINSEQ_1:3; then y <> y + y1 by Lm8; then x <> z by A7,A9,A10,A33,A34,A36,FUNCT_1:def 8; then not z in {x} by TARSKI:def 1; hence thesis by A37,XBOOLE_0:def 4; end; hence thesis by A23,A24,XBOOLE_0:def 2; end; let z be set; assume A38: z in rng q \ {x}; then z in rng q by XBOOLE_0:def 4; then consider y1 such that A39: y1 in dom q and A40: z = q.y1 by FUNCT_1:def 5; A41: y1 in Seg(len q) by A39,FINSEQ_1:def 3; reconsider y1 as Nat by A39; not z in {x} by A38,XBOOLE_0:def 4; then A42: y <> y1 by A10,A40,TARSKI:def 1; A43: now assume A44: y < y1; then consider j such that A45: y1 = y + j by NAT_1:28; A46: 1 <= j by A44,A45,Lm11; y + j <= len q by A41,A45,FINSEQ_1:3; then j <= n by A15,REAL_1:53; then A47: j in Seg n by A46,FINSEQ_1:3; then z = q2.j by A19,A40,A45; hence z in rng q2 by A18,A47,FUNCT_1:def 5; end; now assume y1 < y; then 1 <= y1 & y1 <= k by A13,A41,FINSEQ_1:3,NAT_1:38; then y1 in Seg k by FINSEQ_1:3; then A48: y1 in dom q1 by A20,FINSEQ_1:21; then q1.y1 = z by A40,FUNCT_1:70; hence z in rng q1 by A48,FUNCT_1:def 5; end; then z in rng q1 \/ rng q2 by A42,A43,REAL_1:def 5,XBOOLE_0:def 2; hence thesis by FINSEQ_1:44; end; A49: p = (p ^ <* x *>) | (dom p) by Lm12; A50: rng p = rng(p ^ <* x *>) \ {x} proof thus rng p c= rng(p ^ <* x *>) \ {x} proof let z be set; assume A51: z in rng p; A52: rng p c= rng(p ^ <* x *>) by A49,FUNCT_1:76; consider y1 such that A53: y1 in dom p and A54: p.y1 = z by A51,FUNCT_1:def 5; A55: y1 in Seg(len p) by A53,FINSEQ_1:def 3; reconsider y1 as Nat by A53; A56: (p ^ <* x *>).(len p + 1) = x & (p ^ <* x *>).y1 = p.y1 by A49,A53,FINSEQ_1:59,FUNCT_1:70; A57: y1 <= len p & len p < len p +1 by A55,FINSEQ_1:3,REAL_1:69; then 1 <= y1 & y1 <= len p + 1 by A55,AXIOMS:22,FINSEQ_1:3; then y1 in Seg(len p + 1) & len p + 1 in Seg(len p + 1) by FINSEQ_1:3,6; then y1 in Seg(len p + len<* x *>) & len p + 1 in Seg(len p + len<* x *>) by FINSEQ_1:57; then y1 in dom(p ^ <* x *>) & len p + 1 in dom(p ^ <* x *>) by FINSEQ_1:def 7; then x <> z by A5,A54,A56,A57,FUNCT_1:def 8; then z in rng(p ^ <* x *>) & not z in {x} by A51,A52,TARSKI:def 1; hence thesis by XBOOLE_0:def 4; end; let z be set; assume z in rng(p ^ <* x *>) \ {x}; then z in rng(p ^ <* x *>) & not z in {x} by XBOOLE_0:def 4; then z in rng p \/ rng<* x *> & z <> x by FINSEQ_1:44,TARSKI:def 1; then (z in rng p or z in rng<* x *>) & x <> z by XBOOLE_0:def 2; then (z in rng p or z in {x}) & x <> z by FINSEQ_1:55; hence thesis by TARSKI:def 1; end; A58: q1 ^ q2 is one-to-one proof let y1,y2; assume that A59: y1 in dom(q1 ^ q2) and A60: y2 in dom(q1 ^ q2) and A61: (q1 ^ q2).y1 = (q1 ^ q2).y2; reconsider m1 = y1, m2 = y2 as Nat by A59,A60; A62: q1 is one-to-one by A7,FUNCT_1:84; A63: now assume A64: m1 in dom q1 & m2 in dom q1; then (q1 ^ q2).m1 = q1.m1 & (q1 ^ q2).m2 = q1.m2 by FINSEQ_1:def 7; hence thesis by A61,A62,A64,FUNCT_1:def 8; end; A65: now assume A66: m1 in dom q1; given j such that A67: j in dom q2 and A68: m2 = len q1 + j; (q1 ^ q2).m1 = q1.m1 & (q1 ^ q2).m2 = q2.j & q1.m1 = q.m1 by A66,A67,A68,FINSEQ_1:def 7,FUNCT_1:70; then A69: q.m1 = q.(y + j) by A18,A19,A61,A67; A70: dom q1 c= dom q by FUNCT_1:76; 1 <= j by A18,A67,FINSEQ_1:3; then A71: 1 <= y + j by NAT_1:37; j <= n by A18,A67,FINSEQ_1:3; then y + j <= len q by A15,REAL_1:55; then y + j in Seg(len q) by A71,FINSEQ_1:3; then A72: y + j in dom q by FINSEQ_1:def 3; m1 in Seg k by A20,A66,FINSEQ_1:21; then m1 <= k & k < y by A13,FINSEQ_1:3,REAL_1:69; then m1 < y & y <= y + j by AXIOMS:22,NAT_1:37; hence thesis by A7,A66,A69,A70,A72,FUNCT_1:def 8; end; A73: now assume A74: m2 in dom q1; given j such that A75: j in dom q2 and A76: m1 = len q1 + j; (q1 ^ q2).m2 = q1.m2 & (q1 ^ q2).m1 = q2.j & q1.m2 = q.m2 by A74,A75,A76,FINSEQ_1:def 7,FUNCT_1:70; then A77: q.m2 = q.(y + j) by A18,A19,A61,A75; A78: dom q1 c= dom q by FUNCT_1:76; 1 <= j by A18,A75,FINSEQ_1:3; then A79: 1 <= y + j by NAT_1:37; j <= n by A18,A75,FINSEQ_1:3; then y + j <= len q by A15,REAL_1:55; then y + j in Seg(len q) by A79,FINSEQ_1:3; then A80: y + j in dom q by FINSEQ_1:def 3; m2 in Seg k by A20,A74,FINSEQ_1:21; then m2 <= k & k < y by A13,FINSEQ_1:3,REAL_1:69; then m2 < y & y <= y + j by AXIOMS:22,NAT_1:37; hence thesis by A7,A74,A77,A78,A80,FUNCT_1:def 8; end; now given j1 being Nat such that A81: j1 in dom q2 and A82: m1 = len q1 + j1; given j2 being Nat such that A83: j2 in dom q2 and A84: m2 = len q1 + j2; (q1 ^ q2).m1 = q2.j1 & (q1 ^ q2).m2 = q2.j2 by A81,A82,A83,A84,FINSEQ_1:def 7; then A85: (q1 ^ q2).m1 = q.(y + j1) & (q1 ^ q2).m2 = q.(y + j2) by A18,A19,A81,A83; 1 <= j1 & 1 <= j2 by A18,A81,A83,FINSEQ_1:3; then A86: 1 <= y + j1 & 1 <= y + j2 by NAT_1:37; j1 <= n & j2 <= n by A18,A81,A83,FINSEQ_1:3; then y + j1 <= len q & y + j2 <= len q by A15,REAL_1:55; then y + j1 in Seg(len q) & y + j2 in Seg(len q) by A86,FINSEQ_1:3 ; then y + j1 in dom q & y + j2 in dom q by FINSEQ_1:def 3; then y + j1 = y + j2 by A7,A61,A85,FUNCT_1:def 8; hence thesis by A82,A84,XCMPLX_1:2; end; hence thesis by A59,A60,A63,A65,A73,FINSEQ_1:38; end; len(q1 ^ <* x *>) + len q2 = len q1 + len<* x *> + len q2 by FINSEQ_1: 35 .= k + 1 + len q2 by A21,FINSEQ_1:56 .= len q by A13,A15,A18,FINSEQ_1:def 3; then A87: dom q = Seg(len(q1 ^ <* x *>) + len q2) by FINSEQ_1:def 3; A88: now let j; assume A89: j in dom(q1 ^ <* x *>); A90: now assume j in dom q1; then (q1 ^ <* x *>).j = q1.j & q.j = q1.j by FINSEQ_1:def 7,FUNCT_1:70; hence q.j = (q1 ^ <* x *>).j; end; now given i such that A91: i in dom<* x *> and A92: j = len q1 + i; i in {1} by A91,FINSEQ_1:4,55; then i = 1 by TARSKI:def 1; hence q.j = (q1 ^ <* x *>).j by A10,A13,A21,A92,FINSEQ_1:59; end; hence q.j = (q1 ^ <* x *>).j by A89,A90,FINSEQ_1:38; end; now let j; assume j in dom q2; hence q2.j = q.(len q1 + 1 + j) by A13,A18,A19,A21 .= q.(len q1 + len<* x *> + j) by FINSEQ_1:56 .= q.(len(q1 ^ <* x *>) + j) by FINSEQ_1:35; end; then q1 ^ <* x *> ^ q2 = q by A87,A88,FINSEQ_1:def 7; then A93: len q = len(q1 ^ <* x *>) + len q2 by FINSEQ_1:35 .= len <* x *> + len q1 + len q2 by FINSEQ_1:35 .= 1 + len q1 + len q2 by FINSEQ_1:57 .= 1 + (len q1 + len q2) by XCMPLX_1:1 .= len(q1 ^ q2) + 1 by FINSEQ_1:35; len(p ^ <* x *>) = len p + len<* x *> by FINSEQ_1:35 .= len p + 1 by FINSEQ_1:57; hence len(p ^ <* x *>) = len q by A4,A5,A6,A22,A49,A50,A58,A93,FUNCT_1:84; end; hence thesis; end; for p holds P[p] from IndSeq(A1,A3); hence thesis; end; theorem for V being Abelian add-associative right_zeroed (non empty LoopStr), F,G being FinSequence of the carrier of V st rng F = rng G & F is one-to-one & G is one-to-one holds Sum(F) = Sum(G) proof let V be Abelian add-associative right_zeroed (non empty LoopStr), F,G be FinSequence of the carrier of V; defpred P[set] means for H,I being FinSequence of the carrier of V st len H = $1 & rng H = rng I & H is one-to-one & I is one-to-one holds Sum(H) = Sum (I); A1: P[0] proof now let H,I be FinSequence of the carrier of V; assume that A2: len H = 0 and A3: rng H = rng I and H is one-to-one & I is one-to-one; H = {} by A2,FINSEQ_1:25; then rng H = {} by FINSEQ_1:27; then I = {} by A3,FINSEQ_1:27; then len I = 0 by FINSEQ_1:25; then Sum(H) = 0.V & Sum(I) = 0.V by A2,Lm6; hence Sum(H) = Sum(I); end; hence thesis; end; A4: for k st P[k] holds P[k+1] proof now let k; assume A5: for H,I being FinSequence of the carrier of V st len H = k & rng H = rng I & H is one-to-one & I is one-to-one holds Sum(H) = Sum(I); let H,I be FinSequence of the carrier of V; assume that A6: len H = k + 1 and A7: rng H = rng I and A8: H is one-to-one and A9: I is one-to-one; A10: len H = len I by A7,A8,A9,Lm13; reconsider p = H | (Seg k) as FinSequence of the carrier of V by FINSEQ_1:23; A11: k + 1 in Seg(k + 1) by FINSEQ_1:6; then k + 1 in dom H by A6,FINSEQ_1:def 3; then H.(k + 1) in rng I by A7,FUNCT_1:def 5; then consider x such that A12: x in dom I and A13: H.(k + 1) = I.x by FUNCT_1:def 5; A14: x in Seg(k + 1) by A6,A10,A12,FINSEQ_1:def 3; reconsider n = x as Nat by A12; reconsider v = H.(k + 1) as Element of V by A6,A11,Th54; A15: 1 <= n by A14,FINSEQ_1:3; then consider m1 being Nat such that A16: 1 + m1 = n by NAT_1:28; A17: n <= k + 1 by A14,FINSEQ_1:3; then consider m2 being Nat such that A18: n + m2 = k + 1 by NAT_1:28; reconsider q1 = I | (Seg m1) as FinSequence of the carrier of V by FINSEQ_1:23; defpred P[Nat,set] means $2 = I.(n + $1); A19: for j,y1,y2 st j in Seg m2 & P[j,y1] & P[j,y2] holds y1 = y2; A20: for j st j in Seg m2 ex x st P[j,x]; consider q2 being FinSequence such that A21: dom q2 = Seg m2 and A22: for k st k in Seg m2 holds P[k,q2.k] from SeqEx(A19,A20); rng q2 c= the carrier of V proof let x; assume x in rng q2; then consider y such that A23: y in dom q2 and A24: x = q2.y by FUNCT_1:def 5; reconsider y as Nat by A23; 1 <= y & y <= n + y by A21,A23,FINSEQ_1:3,NAT_1:37; then A25: 1 <= n + y by AXIOMS:22; y <= m2 by A21,A23,FINSEQ_1:3; then n + y <= len I by A6,A10,A18,REAL_1:55; then n + y in Seg(len I) by A25,FINSEQ_1:3; then reconsider xx = I.(n + y) as Element of V by Th54; xx in the carrier of V; hence thesis by A21,A22,A23,A24; end; then reconsider q2 as FinSequence of the carrier of V by FINSEQ_1:def 4; set q = q1 ^ q2; k <= k + 1 by NAT_1:37; then A26: len p = k by A6,FINSEQ_1:21; m1 <= n by A16,NAT_1:29; then A27: m1 <= k + 1 by A17,AXIOMS:22; then A28: len q1 = m1 & len q2 = m2 by A6,A10,A21,FINSEQ_1:21,def 3; then len(q1 ^ <* v *>) + len q2 = len q1 + len<* v *> + m2 by FINSEQ_1:35 .= k + 1 by A16,A18,A28,FINSEQ_1:57; then A29: dom I = Seg(len(q1 ^ <* v *>) + len q2) by A6,A10,FINSEQ_1:def 3; A30: now let j; assume A31: j in dom(q1 ^ <* v *>); len(q1 ^ <* v *>) = m1 + len <* v *> by A28,FINSEQ_1:35 .= m1 + 1 by FINSEQ_1:57; then j in Seg(m1 + 1) by A31,FINSEQ_1:def 3; then A32: j in Seg m1 \/ {n} by A16,FINSEQ_1:11; A33: now assume j in Seg m1; then A34: j in dom q1 by A6,A10,A27,FINSEQ_1:21; then q1.j = I.j by FUNCT_1:70; hence I.j = (q1 ^ <* v *>).j by A34,FINSEQ_1:def 7; end; now assume j in {n}; then A35: j = n by TARSKI:def 1; 1 in Seg 1 & len<* v *> = 1 by FINSEQ_1:3,56; then 1 in dom <* v *> by FINSEQ_1:def 3; then (q1 ^ <* v *>).(len q1 + 1) = <* v *>.1 by FINSEQ_1:def 7; hence (q1 ^ <* v *>).j = I.j by A13,A16,A28,A35,FINSEQ_1:57; end; hence I.j = (q1 ^ <* v *>).j by A32,A33,XBOOLE_0:def 2; end; now let j; assume A36: j in dom q2; len(q1 ^ <* v *>) = m1 + len<* v *> by A28,FINSEQ_1:35 .= n by A16,FINSEQ_1:56; hence I.(len(q1 ^ <* v *>) + j) = q2.j by A21,A22,A36; end; then A37: I = q1 ^ <* v *> ^ q2 by A29,A30,FINSEQ_1:def 7; then A38: rng I = rng(q1 ^ <* v *>) \/ rng q2 by FINSEQ_1:44 .= rng <* v *> \/ rng q1 \/ rng q2 by FINSEQ_1:44 .= {v} \/ rng q1 \/ rng q2 by FINSEQ_1:56 .= {v} \/ (rng q1 \/ rng q2) by XBOOLE_1:4 .= {v} \/ rng q by FINSEQ_1:44; A39: m1 < n by A16,REAL_1:69; {v} misses rng q proof assume not thesis; then A40: {v} /\ rng q <> {} by XBOOLE_0:def 7; consider y being Element of {v} /\ rng q; y in rng q by A40,XBOOLE_0:def 3; then A41: y in rng q1 \/ rng q2 by FINSEQ_1:44; A42: y in {v} by A40,XBOOLE_0:def 3; then A43: y = I.n by A13,TARSKI:def 1; A44: now assume y in rng q1; then consider y1 such that A45: y1 in dom q1 and A46: y = q1.y1 by FUNCT_1:def 5; A47: y1 in Seg m1 by A6,A10,A27,A45,FINSEQ_1:21; reconsider y1 as Nat by A45; A48: q1.y1 = I.y1 by A45,FUNCT_1:70; A49: y1 <= m1 by A47,FINSEQ_1:3; A50: y1 <> n by A39,A47,FINSEQ_1:3; 1 <= y1 & y1 <= k + 1 by A27,A47,A49,AXIOMS:22,FINSEQ_1:3; then y1 in Seg(k + 1) by FINSEQ_1:3; then y1 in dom I & n in dom I & I.y1 = I.n by A6,A10,A12,A13,A42,A46,A48,FINSEQ_1:def 3,TARSKI :def 1; hence contradiction by A9,A50,FUNCT_1:def 8; end; now assume y in rng q2; then consider y1 such that A51: y1 in dom q2 and A52: y = q2.y1 by FUNCT_1:def 5; reconsider y1 as Nat by A51; A53: I.n = I.(n + y1) by A21,A22,A43,A51,A52; A54: 1 <= n + y1 by A15,NAT_1:37; y1 <= m2 by A21,A51,FINSEQ_1:3; then n + y1 <= k + 1 by A18,REAL_1:55; then n + y1 in Seg(k + 1) by A54,FINSEQ_1:3; then n in dom I & n + y1 in dom I by A6,A10,A12,FINSEQ_1:def 3 ; then A55: n = n + y1 by A9,A53,FUNCT_1:def 8; y1 <> 0 by A21,A51,FINSEQ_1:3; hence contradiction by A55,Lm8; end; hence thesis by A41,A44,XBOOLE_0:def 2; end; then A56: rng q = rng I \ {v} by A38,XBOOLE_1:88; A57: Seg k = Seg(k + 1) \ {k + 1} by Lm9; A58: rng p = H .: (Seg k) by RELAT_1:148; A59: Seg(k + 1) = dom H by A6,FINSEQ_1:def 3; then A60: rng H = H .: (Seg(k + 1)) by RELAT_1:146; H .: (Seg k) = H .: Seg(k + 1) \ H .: {k + 1} by A8,A57,FUNCT_1:123; then A61: rng p = rng q by A7,A11,A56,A58,A59,A60,FUNCT_1:117; A62: p is one-to-one by A8,FUNCT_1:84; A63: q is one-to-one proof let y1,y2 be set; assume that A64: y1 in dom q and A65: y2 in dom q and A66: q.y1 = q .y2; reconsider x1 = y1, x2 = y2 as Nat by A64,A65; A67: q1 is one-to-one by A9,FUNCT_1:84; A68: now assume A69: x1 in dom q1 & x2 in dom q1; then q1.x1 = q.x1 & q1.x2 = q.x2 by FINSEQ_1:def 7; hence thesis by A66,A67,A69,FUNCT_1:def 8; end; A70: now assume A71: x1 in dom q1; given j such that A72: j in dom q2 and A73: x2 = len q1 + j; q1.x1 = I.x1 by A71,FUNCT_1:70; then A74: q.x1 = I.x1 by A71,FINSEQ_1:def 7; q2.j = I.(n + j) by A21,A22,A72; then A75: I.x1 = I.(n + j) by A66,A72,A73,A74,FINSEQ_1:def 7; x1 in Seg m1 by A6,A10,A27,A71,FINSEQ_1:21; then A76: 1 <= x1 & x1 <= m1 by FINSEQ_1:3; then A77: x1 <= k + 1 by A27,AXIOMS:22; A78: 1 <= n + j by A15,NAT_1:37; j <= m2 by A21,A72,FINSEQ_1:3; then n + j <= k + 1 by A18,REAL_1:55; then n + j in Seg(k + 1) & x1 in Seg(k + 1) by A76,A77,A78,FINSEQ_1:3; then A79: x1 in dom I & n + j in dom I by A6,A10,FINSEQ_1:def 3; x1 < n & n <= n + j by A39,A76,AXIOMS:22,NAT_1:37; hence thesis by A9,A75,A79,FUNCT_1:def 8; end; A80: now assume A81: x2 in dom q1; given j such that A82: j in dom q2 and A83: x1 = len q1 + j; q1.x2 = I.x2 by A81,FUNCT_1:70; then A84: q.x2 = I.x2 by A81,FINSEQ_1:def 7; q2.j = I.(n + j) by A21,A22,A82; then A85: I.x2 = I.(n + j) by A66,A82,A83,A84,FINSEQ_1:def 7; x2 in Seg m1 by A6,A10,A27,A81,FINSEQ_1:21; then A86: 1 <= x2 & x2 <= m1 by FINSEQ_1:3; then A87: x2 <= k + 1 by A27,AXIOMS:22; A88: 1 <= n + j by A15,NAT_1:37; j <= m2 by A21,A82,FINSEQ_1:3; then n + j <= k + 1 by A18,REAL_1:55; then n + j in Seg(k + 1) & x2 in Seg(k + 1) by A86,A87,A88,FINSEQ_1:3; then A89: x2 in dom I & n + j in dom I by A6,A10,FINSEQ_1:def 3; x2 < n & n <= n + j by A39,A86,AXIOMS:22,NAT_1:37; hence thesis by A9,A85,A89,FUNCT_1:def 8; end; now given j1 being Nat such that A90: j1 in dom q2 and A91: x1 = len q1 + j1; given j2 being Nat such that A92: j2 in dom q2 and A93: x2 = len q1 + j2; A94: q2.j1 = I.(n + j1) & q2.j2 = I.(n + j2) by A21,A22,A90, A92; A95: q2.j1 = q.(m1 + j2) by A28,A66,A90,A91,A93,FINSEQ_1:def 7 .= q2.j2 by A28,A92,FINSEQ_1:def 7; A96: 1 <= n + j1 & 1 <= n + j2 by A15,NAT_1:37; j1 <= m2 & j2 <= m2 by A21,A90,A92,FINSEQ_1:3; then n + j1 <= k + 1 & n + j2 <= k + 1 by A18,REAL_1:55; then n + j1 in Seg(k + 1) & n + j2 in Seg(k + 1) by A96,FINSEQ_1:3; then n + j1 in dom I & n + j2 in dom I by A6,A10,FINSEQ_1:def 3; then n + j1 = n + j2 by A9,A94,A95,FUNCT_1:def 8; hence thesis by A91,A93,XCMPLX_1:2; end; hence thesis by A64,A65,A68,A70,A80,FINSEQ_1:38; end; A97: len<* v *> = 1 by FINSEQ_1:56; A98: for k st k in dom p holds H.k=p.k by FUNCT_1:70; now let k; assume k in dom<* v *>; then k in Seg 1 by FINSEQ_1:55; then k = 1 by FINSEQ_1:4,TARSKI:def 1; hence H.(len p + k) = <* v *>.k by A26,FINSEQ_1:57; end; then H = p ^ <* v *> by A26,A59,A97,A98,FINSEQ_1:def 7; then A99: Sum(H) = Sum(p) + Sum<* v *> by Th58; Sum(I) = Sum(q1 ^ <* v *>) + Sum(q2) by A37,Th58 .= (Sum(q1) + Sum<* v *>) + Sum(q2) by Th58 .= Sum<* v *> + (Sum(q1) + Sum(q2)) by Def6 .= Sum(q) + Sum<* v *> by Th58; hence Sum(H) = Sum(I) by A5,A26,A61,A62,A63,A99; end; hence thesis; end; A100: for k holds P[k] from Ind(A1,A4); len F = len F; hence thesis by A100; end; theorem for V being non empty LoopStr holds Sum(<*>(the carrier of V)) = 0.V by Lm5; theorem for V being add-associative right_zeroed right_complementable (non empty LoopStr), v being Element of V holds Sum<* v *> = v by Lm10; theorem Th62: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,u being Element of V holds Sum<* v,u *> = v + u proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v,u be Element of V; <* v,u *> = <* v *> ^ <* u *> by FINSEQ_1:def 9; hence Sum<* v,u *> = Sum<* v *> + Sum<* u *> by Th58 .= v + Sum<* u *> by Lm10 .= v + u by Lm10; end; theorem Th63: for V being add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* v,u,w *> = v + u + w proof let V be add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; <* v,u,w *> = <* v,u *> ^ <* w *> by FINSEQ_1:60; hence Sum<* v,u,w *> = Sum<* v,u *> + Sum<* w *> by Th58 .= Sum<* v,u *> + w by Lm10 .= v + u + w by Th62; end; theorem for V being RealLinearSpace, a being Real holds a * Sum(<*>(the carrier of V)) = 0.V proof let V be RealLinearSpace, a be Real; thus a * Sum(<*>(the carrier of V)) = a * 0.V by Lm5 .= 0.V by Th23; end; canceled; theorem for V being RealLinearSpace, a being Real, v,u being VECTOR of V holds a * Sum<* v,u *> = a * v + a * u proof let V be RealLinearSpace, a be Real, v,u be VECTOR of V; thus a * Sum<* v,u *> = a * (v + u) by Th62 .= a * v + a * u by Def9; end; theorem for V being RealLinearSpace, a being Real, v,u,w being VECTOR of V holds a * Sum<* v,u,w *> = a * v + a * u + a * w proof let V be RealLinearSpace, a be Real, v,u,w be VECTOR of V; thus a * Sum<* v,u,w *> = a * (v + u + w) by Th63 .= a * (v + u) + a * w by Def9 .= a * v + a * u + a * w by Def9; end; theorem - Sum(<*>(the carrier of V)) = 0.V proof thus - Sum(<*>(the carrier of V)) = - 0.V by Lm5 .= 0.V by Th25; end; theorem - Sum<* v *> = - v by Lm10; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u being Element of V holds - Sum<* v,u *> = (- v) - u proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u be Element of V; thus - Sum<* v,u *> = - (v + u) by Th62 .= (- v) - u by Th44; end; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds - Sum<* v,u,w *> = ((- v) - u) - w proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus - Sum<* v,u,w *> = - (v + u + w) by Th63 .= (- (v + u)) - w by Th44 .= ((- v) - u) - w by Th44; end; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,w being Element of V holds Sum<* v,w *> = Sum<* w,v *> proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,w be Element of V; thus Sum<* v,w *> = v + w by Th62 .= Sum<* w,v *> by Th62; end; theorem Sum<* v,w *> = Sum<* v *> + Sum<* w *> proof thus Sum<* v,w *> = v + w by Th62 .= Sum<* v *> + w by Lm10 .= Sum<* v *> + Sum<* w *> by Lm10; end; theorem Sum<* 0.V,0.V *> = 0.V proof thus Sum<* 0.V,0.V *> = 0.V + 0.V by Th62 .= 0.V by Th10; end; theorem Sum<* 0.V,v *> = v & Sum<* v,0.V *> = v proof thus Sum<* 0.V,v *> = 0.V + v by Th62 .= v by Th10; thus Sum<* v,0.V *> = v + 0.V by Th62 .= v by Th10; end; theorem Sum<* v,- v *> = 0.V & Sum<* - v,v *> = 0.V proof A1: v + - v = 0.V by Def10; hence Sum<* v,- v *> = 0.V by Th62; - v + v = 0.V by A1,Lm2; hence Sum<* - v, v *> = 0.V by Th62; end; theorem Sum<* v,- w *> = v - w proof thus Sum<* v,- w *> = v + (- w) by Th62 .= v - w by Def11; end; theorem Th78: Sum<* - v,- w *> = - (w + v) proof thus Sum<* - v,- w *> = (- v) + (- w) by Th62 .= - (w + v) by Lm4; end; theorem Th79: for V being RealLinearSpace, v being VECTOR of V holds Sum<* v,v *> = 2 * v proof let V be RealLinearSpace, v be VECTOR of V; thus Sum<* v,v *> = v + v by Th62 .= 1 * v + v by Def9 .= 1 * v + 1 * v by Def9 .= (1 + 1) * v by Def9 .= 2 * v; end; theorem for V being RealLinearSpace, v being VECTOR of V holds Sum<* - v,- v *> = (- 2) * v proof let V be RealLinearSpace, v be VECTOR of V; thus Sum<* - v,- v *> = - (v + v) by Th78 .= - Sum<* v,v *> by Th62 .= - (2 * v) by Th79 .= (- 1) * (2 * v) by Th29 .= ((- 1) * 2) * v by Def9 .= (- 2) * v; end; theorem Sum<* u,v,w *> = Sum<* u *> + Sum<* v *> + Sum<* w *> proof thus Sum<* u,v,w *> = u + v + w by Th63 .= Sum<* u *> + v + w by Lm10 .= Sum<* u *> + v + Sum<* w *> by Lm10 .= Sum<* u *> + Sum<* v *> + Sum<* w *> by Lm10; end; theorem Sum<* u,v,w *> = Sum<* u,v *> + w proof thus Sum<* u,v,w *> = u + v + w by Th63 .= Sum<* u,v *> + w by Th62; end; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* u,v,w *> = Sum<* v,w *> + u proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus Sum<* u,v,w *> = u + v + w by Th63 .= u + (v + w) by Def6 .= Sum<* v,w *> + u by Th62; end; theorem Th84: for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* u,v,w *> = Sum<* u,w *> + v proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus Sum<* u,v,w *> = u + v + w by Th63 .= u + w + v by Def6 .= Sum<* u,w *> + v by Th62; end; theorem Th85: for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* u,v,w *> = Sum<* u,w,v *> proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus Sum<* u,v,w *> = u + v + w by Th63 .= u + w + v by Def6 .= Sum<* u,w,v *> by Th63; end; theorem Th86: for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* u,v,w *> = Sum<* v,u,w *> proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus Sum<* u,v,w *> = u + v + w by Th63 .= Sum<* v,u,w *> by Th63; end; theorem Th87: for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* u,v,w *> = Sum<* v,w,u *> proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus Sum<* u,v,w *> = Sum<* v,u,w *> by Th86 .= Sum<* v,w,u *> by Th85; end; canceled; theorem for V being Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w being Element of V holds Sum<* u,v,w *> = Sum<* w,v,u *> proof let V be Abelian add-associative right_zeroed right_complementable (non empty LoopStr), v,u,w be Element of V; thus Sum<* u,v,w *> = Sum<* w,u,v *> by Th87 .= Sum<* w,v,u *> by Th85; end; theorem Sum<* 0.V,0.V,0.V *> = 0.V proof thus Sum<* 0.V,0.V,0.V *> = 0.V + 0.V + 0.V by Th63 .= 0.V + 0.V by Th10 .= 0.V by Th10; end; theorem Sum<* 0.V,0.V,v *> = v & Sum<* 0.V,v,0.V *> = v & Sum<* v,0.V,0.V *> = v proof thus Sum<* 0.V,0.V,v *> = 0.V + 0.V + v by Th63 .= 0.V + v by Th10 .= v by Th10; thus Sum<* 0.V,v,0.V *> = 0.V + v + 0.V by Th63 .= 0.V + v by Th10 .= v by Th10; thus Sum<* v,0.V,0.V *> = v + 0.V + 0.V by Th63 .= v + 0.V by Th10 .= v by Th10; end; theorem Sum<* 0.V,u,v *> = u + v & Sum<* u,v,0.V *> = u + v & Sum<* u,0.V,v *> = u + v proof thus Sum<* 0.V,u,v *> = 0.V + u + v by Th63 .= u + v by Th10; thus Sum<* u,v,0.V *> = u + v + 0.V by Th63 .= u + v by Th10; thus Sum<* u,0.V,v *> = u + 0.V + v by Th63 .= u + v by Th10; end; theorem for V being RealLinearSpace, v being VECTOR of V holds Sum<* v,v,v *> = 3 * v proof let V be RealLinearSpace, v be VECTOR of V; thus Sum<* v,v,v *> = Sum<* v,v *> + v by Th84 .= 2 * v + v by Th79 .= 2 * v + 1 * v by Def9 .= (2 + 1) * v by Def9 .= 3 * v; end; theorem len F = 0 implies Sum(F) = 0.V by Lm6; theorem len F = 1 implies Sum(F) = F.1 proof assume A1: len F = 1; then dom F = {1} by FINSEQ_1:4,def 3; then 1 in dom F by TARSKI:def 1; then F.1 in rng F & rng F c= the carrier of V by FINSEQ_1:def 4,FUNCT_1:def 5; then reconsider v = F.1 as Element of V; F = <* v *> by A1,FINSEQ_1:57; hence thesis by Lm10; end; theorem len F = 2 & v1 = F.1 & v2 = F.2 implies Sum(F) = v1 + v2 proof assume len F = 2 & v1 = F.1 & v2 = F.2; then F = <* v1,v2 *> by FINSEQ_1:61; hence thesis by Th62; end; theorem len F = 3 & v1 = F.1 & v2 = F.2 & v = F.3 implies Sum(F) = v1 + v2 + v proof assume len F = 3 & v1 = F.1 & v2 = F.2 & v = F.3; then F = <* v1,v2,v *> by FINSEQ_1:62; hence thesis by Th63; end; :: :: Auxiliary theorems. :: definition let R be non empty ZeroStr, a be Element of R; attr a is non-zero means a <> 0.R; end; reserve j, k, n for natural number; theorem j < 1 implies j = 0 by Lm7; theorem 1 <= k iff k <> 0 by Lm7; canceled 2; theorem k <> 0 implies n < n + k by Lm8; theorem k < k + n iff 1 <= n by Lm11; theorem Seg k = Seg(k + 1) \ {k + 1} by Lm9; theorem p = (p ^ q) | (dom p) by Lm12; theorem rng p = rng q & p is one-to-one & q is one-to-one implies len p = len q by Lm13;