let U be non empty set ; :: thesis: for S being Language
for E being Equivalence_Relation of U
for I being b1,U -interpreter-like b2 -respecting Function holds (I quotient E) -TermEval = (E -class) * (I -TermEval)

let S be Language; :: thesis: for E being Equivalence_Relation of U
for I being S,U -interpreter-like b1 -respecting Function holds (I quotient E) -TermEval = (E -class) * (I -TermEval)

let E be Equivalence_Relation of U; :: thesis: for I being S,U -interpreter-like E -respecting Function holds (I quotient E) -TermEval = (E -class) * (I -TermEval)
set u = the Element of U;
let I be S,U -interpreter-like E -respecting Function; :: thesis: (I quotient E) -TermEval = (E -class) * (I -TermEval)
reconsider e = (E -class) . the Element of U as Element of Class E ;
set F = S -firstChar ;
set II = I quotient E;
set te = (I, the Element of U) -TermEval ;
set TE = ((I quotient E),e) -TermEval ;
set O = OwnSymbolsOf S;
set TT = AllTermsOf S;
set tee = I -TermEval ;
set TEE = (I quotient E) -TermEval ;
set T = S -termsOfMaxDepth ;
reconsider TF = S -termsOfMaxDepth as Function ;
now :: thesis: for tt being Element of AllTermsOf S holds ((I quotient E) -TermEval) . tt = ((E -class) * (I -TermEval)) . tt
let tt be Element of AllTermsOf S; :: thesis: ((I quotient E) -TermEval) . tt = ((E -class) * (I -TermEval)) . tt
consider mm being Element of NAT such that
A1: tt in TF . mm by FOMODEL1:5;
set v = I -TermEval tt;
set V = (I quotient E) -TermEval tt;
reconsider MM = mm + 1 as Element of NAT ;
((I, the Element of U) -TermEval) . MM is Element of Funcs ((AllTermsOf S),U) ;
then A2: ( dom (((I, the Element of U) -TermEval) . MM) = AllTermsOf S & dom (I -TermEval) = AllTermsOf S ) by FUNCT_2:def 1;
thus ((I quotient E) -TermEval) . tt = (I quotient E) -TermEval tt by FOMODEL2:def 10
.= ((((I quotient E),e) -TermEval) . (mm + 1)) . tt by FOMODEL2:def 9, A1
.= ((E -class) * (((I, the Element of U) -TermEval) . (mm + 1))) . tt by Lm24
.= (E -class) . ((((I, the Element of U) -TermEval) . (mm + 1)) . tt) by FUNCT_1:13, A2
.= (E -class) . (I -TermEval tt) by FOMODEL2:def 9, A1
.= (E -class) . ((I -TermEval) . tt) by FOMODEL2:def 10
.= ((E -class) * (I -TermEval)) . tt by A2, FUNCT_1:13 ; :: thesis: verum
end;
hence (I quotient E) -TermEval = (E -class) * (I -TermEval) by FUNCT_2:63; :: thesis: verum