let D be non empty set ; for RD being Equivalence_Relation of D
for a, b being Element of D
for F being BinOp of D,RD holds (F /\/ RD) . (Class RD,a),(Class RD,b) = Class RD,(F . a,b)
let RD be Equivalence_Relation of D; for a, b being Element of D
for F being BinOp of D,RD holds (F /\/ RD) . (Class RD,a),(Class RD,b) = Class RD,(F . a,b)
let a, b be Element of D; for F being BinOp of D,RD holds (F /\/ RD) . (Class RD,a),(Class RD,b) = Class RD,(F . a,b)
let F be BinOp of D,RD; (F /\/ RD) . (Class RD,a),(Class RD,b) = Class RD,(F . a,b)
A1:
b in EqClass RD,b
by EQREL_1:28;
a in EqClass RD,a
by EQREL_1:28;
hence
(F /\/ RD) . (Class RD,a),(Class RD,b) = Class RD,(F . a,b)
by A1, Def4; verum