let f be non empty with_zero FinSequence of NAT ; :: thesis: for D being disjoint_with_NAT set holds FreeGenSetZAO f,D is free
let D be disjoint_with_NAT set ; :: thesis: FreeGenSetZAO f,D is free
set fgs = FreeGenSetZAO f,D;
set fua = FreeUnivAlgZAO f,D;
let U1 be Universal_Algebra; :: according to FREEALG:def 6 :: thesis: ( FreeUnivAlgZAO f,D,U1 are_similar implies for f being Function of (FreeGenSetZAO f,D),the carrier of U1 ex h being Function of (FreeUnivAlgZAO f,D),U1 st
( h is_homomorphism FreeUnivAlgZAO f,D,U1 & h | (FreeGenSetZAO f,D) = f ) )

assume A1: FreeUnivAlgZAO f,D,U1 are_similar ; :: thesis: for f being Function of (FreeGenSetZAO f,D),the carrier of U1 ex h being Function of (FreeUnivAlgZAO f,D),U1 st
( h is_homomorphism FreeUnivAlgZAO f,D,U1 & h | (FreeGenSetZAO f,D) = f )

set A = DTConUA f,D;
set c1 = the carrier of U1;
set cf = the carrier of (FreeUnivAlgZAO f,D);
let F be Function of (FreeGenSetZAO f,D),the carrier of U1; :: thesis: ex h being Function of (FreeUnivAlgZAO f,D),U1 st
( h is_homomorphism FreeUnivAlgZAO f,D,U1 & h | (FreeGenSetZAO f,D) = F )

deffunc H1( Symbol of (DTConUA f,D)) -> Element of the carrier of U1 = pi F,$1;
deffunc H2( Symbol of (DTConUA f,D), FinSequence, set ) -> Element of the carrier of U1 = (oper (@ $1),U1) /. $3;
consider ff being Function of (TS (DTConUA f,D)),the carrier of U1 such that
A2: for t being Symbol of (DTConUA f,D) st t in Terminals (DTConUA f,D) holds
ff . (root-tree t) = H1(t) and
A3: for nt being Symbol of (DTConUA f,D)
for ts being FinSequence of TS (DTConUA f,D) st nt ==> roots ts holds
ff . (nt -tree ts) = H2(nt, roots ts,ff * ts) from DTCONSTR:sch 8();
reconsider ff = ff as Function of (FreeUnivAlgZAO f,D),U1 ;
take ff ; :: thesis: ( ff is_homomorphism FreeUnivAlgZAO f,D,U1 & ff | (FreeGenSetZAO f,D) = F )
for n being Element of NAT st n in dom the charact of (FreeUnivAlgZAO f,D) holds
for o1 being operation of (FreeUnivAlgZAO f,D)
for o2 being operation of U1 st o1 = the charact of (FreeUnivAlgZAO f,D) . n & o2 = the charact of U1 . n holds
for x being FinSequence of (FreeUnivAlgZAO f,D) st x in dom o1 holds
ff . (o1 . x) = o2 . (ff * x)
proof
A4: dom the charact of U1 = Seg (len the charact of U1) by FINSEQ_1:def 3;
let n be Element of NAT ; :: thesis: ( n in dom the charact of (FreeUnivAlgZAO f,D) implies for o1 being operation of (FreeUnivAlgZAO f,D)
for o2 being operation of U1 st o1 = the charact of (FreeUnivAlgZAO f,D) . n & o2 = the charact of U1 . n holds
for x being FinSequence of (FreeUnivAlgZAO f,D) st x in dom o1 holds
ff . (o1 . x) = o2 . (ff * x) )

assume A5: n in dom the charact of (FreeUnivAlgZAO f,D) ; :: thesis: for o1 being operation of (FreeUnivAlgZAO f,D)
for o2 being operation of U1 st o1 = the charact of (FreeUnivAlgZAO f,D) . n & o2 = the charact of U1 . n holds
for x being FinSequence of (FreeUnivAlgZAO f,D) st x in dom o1 holds
ff . (o1 . x) = o2 . (ff * x)

let o1 be operation of (FreeUnivAlgZAO f,D); :: thesis: for o2 being operation of U1 st o1 = the charact of (FreeUnivAlgZAO f,D) . n & o2 = the charact of U1 . n holds
for x being FinSequence of (FreeUnivAlgZAO f,D) st x in dom o1 holds
ff . (o1 . x) = o2 . (ff * x)

let o2 be operation of U1; :: thesis: ( o1 = the charact of (FreeUnivAlgZAO f,D) . n & o2 = the charact of U1 . n implies for x being FinSequence of (FreeUnivAlgZAO f,D) st x in dom o1 holds
ff . (o1 . x) = o2 . (ff * x) )

assume that
A6: o1 = the charact of (FreeUnivAlgZAO f,D) . n and
A7: o2 = the charact of U1 . n ; :: thesis: for x being FinSequence of (FreeUnivAlgZAO f,D) st x in dom o1 holds
ff . (o1 . x) = o2 . (ff * x)

let x be FinSequence of (FreeUnivAlgZAO f,D); :: thesis: ( x in dom o1 implies ff . (o1 . x) = o2 . (ff * x) )
assume A8: x in dom o1 ; :: thesis: ff . (o1 . x) = o2 . (ff * x)
reconsider xa = x as FinSequence of TS (DTConUA f,D) ;
dom (roots xa) = dom xa by TREES_3:def 18
.= Seg (len xa) by FINSEQ_1:def 3 ;
then A9: len (roots xa) = len xa by FINSEQ_1:def 3;
reconsider xa = xa as FinSequence of FinTrees the carrier of (DTConUA f,D) ;
reconsider rxa = roots xa as FinSequence of (dom f) \/ D ;
reconsider rxa = rxa as Element of ((dom f) \/ D) * by FINSEQ_1:def 11;
dom o1 = (arity o1) -tuples_on the carrier of (FreeUnivAlgZAO f,D) by UNIALG_2:2
.= { w where w is Element of the carrier of (FreeUnivAlgZAO f,D) * : len w = arity o1 } ;
then A10: ex w being Element of the carrier of (FreeUnivAlgZAO f,D) * st
( x = w & len w = arity o1 ) by A8;
A11: o1 = FreeOpZAO n,f,D by A5, A6, Def18;
reconsider fx = ff * x as Element of the carrier of U1 * ;
A12: dom o2 = (arity o2) -tuples_on the carrier of U1 by UNIALG_2:2
.= { v where v is Element of the carrier of U1 * : len v = arity o2 } ;
A13: ( len the charact of (FreeUnivAlgZAO f,D) = len the charact of U1 & dom the charact of (FreeUnivAlgZAO f,D) = Seg (len the charact of (FreeUnivAlgZAO f,D)) ) by A1, FINSEQ_1:def 3, UNIALG_2:3;
A14: Seg (len (FreeOpSeqZAO f,D)) = dom (FreeOpSeqZAO f,D) by FINSEQ_1:def 3;
A15: ( len (FreeOpSeqZAO f,D) = len f & dom f = Seg (len f) ) by Def18, FINSEQ_1:def 3;
then reconsider nt = n as Symbol of (DTConUA f,D) by A5, A14, XBOOLE_0:def 3;
reconsider nd = n as Element of (dom f) \/ D by A5, A15, A14, XBOOLE_0:def 3;
A16: f = signature (FreeUnivAlgZAO f,D) by Th7;
then A17: (signature (FreeUnivAlgZAO f,D)) . n = arity o1 by A5, A6, A15, A14, UNIALG_1:def 11;
then [nd,rxa] in REL f,D by A5, A15, A14, A16, A10, A9, Def8;
then A18: nt ==> roots xa by LANG1:def 1;
then A19: ff . (nt -tree xa) = (oper (@ nt),U1) /. (ff * x) by A3;
@ nt = n by A18, Def16;
then A20: oper (@ nt),U1 = o2 by A5, A7, A13, A4, Def4;
signature (FreeUnivAlgZAO f,D) = signature U1 by A1, UNIALG_2:def 2;
then ( len (ff * x) = len x & arity o2 = len x ) by A5, A7, A15, A14, A16, A10, A17, ALG_1:1, UNIALG_1:def 11;
then A21: fx in { v where v is Element of the carrier of U1 * : len v = arity o2 } ;
reconsider xa = xa as Element of (TS (DTConUA f,D)) * by FINSEQ_1:def 11;
Sym n,f,D = nt by A5, A15, A14, Def10;
then o1 . x = nt -tree xa by A5, A8, A15, A14, A11, Def17;
hence ff . (o1 . x) = o2 . (ff * x) by A19, A20, A12, A21, PARTFUN1:def 8; :: thesis: verum
end;
hence ff is_homomorphism FreeUnivAlgZAO f,D,U1 by A1, ALG_1:def 1; :: thesis: ff | (FreeGenSetZAO f,D) = F
A22: the carrier of (FreeUnivAlgZAO f,D) /\ (FreeGenSetZAO f,D) = FreeGenSetZAO f,D by XBOOLE_1:28;
A23: ( dom (ff | (FreeGenSetZAO f,D)) = (dom ff) /\ (FreeGenSetZAO f,D) & dom ff = the carrier of (FreeUnivAlgZAO f,D) ) by FUNCT_2:def 1, RELAT_1:90;
A24: now
let x be set ; :: thesis: ( x in dom F implies (ff | (FreeGenSetZAO f,D)) . x = F . x )
assume A25: x in dom F ; :: thesis: (ff | (FreeGenSetZAO f,D)) . x = F . x
then x in { (root-tree t) where t is Symbol of (DTConUA f,D) : t in Terminals (DTConUA f,D) } ;
then consider s being Symbol of (DTConUA f,D) such that
A26: ( x = root-tree s & s in Terminals (DTConUA f,D) ) ;
thus (ff | (FreeGenSetZAO f,D)) . x = ff . x by A23, A22, A25, FUNCT_1:70
.= pi F,s by A2, A26
.= F . x by A26, Def21 ; :: thesis: verum
end;
FreeGenSetZAO f,D = dom F by FUNCT_2:def 1;
hence ff | (FreeGenSetZAO f,D) = F by A23, A22, A24, FUNCT_1:9; :: thesis: verum