let D be non empty set ; for d being Element of D
for F, G being BinOp of D st F is associative & F is having_a_unity & F is having_an_inverseOp & G is_distributive_wrt F holds
(G [;] d,(id D)) . (the_unity_wrt F) = the_unity_wrt F
let d be Element of D; for F, G being BinOp of D st F is associative & F is having_a_unity & F is having_an_inverseOp & G is_distributive_wrt F holds
(G [;] d,(id D)) . (the_unity_wrt F) = the_unity_wrt F
let F, G be BinOp of D; ( F is associative & F is having_a_unity & F is having_an_inverseOp & G is_distributive_wrt F implies (G [;] d,(id D)) . (the_unity_wrt F) = the_unity_wrt F )
assume that
A1:
F is associative
and
A2:
F is having_a_unity
and
A3:
F is having_an_inverseOp
and
A4:
G is_distributive_wrt F
; (G [;] d,(id D)) . (the_unity_wrt F) = the_unity_wrt F
set e = the_unity_wrt F;
set i = the_inverseOp_wrt F;
G . d,(the_unity_wrt F) =
G . d,(F . (the_unity_wrt F),(the_unity_wrt F))
by A2, SETWISEO:23
.=
F . (G . d,(the_unity_wrt F)),(G . d,(the_unity_wrt F))
by A4, BINOP_1:23
;
then
the_unity_wrt F = F . (F . (G . d,(the_unity_wrt F)),(G . d,(the_unity_wrt F))),((the_inverseOp_wrt F) . (G . d,(the_unity_wrt F)))
by A1, A2, A3, Th63;
then
the_unity_wrt F = F . (G . d,(the_unity_wrt F)),(F . (G . d,(the_unity_wrt F)),((the_inverseOp_wrt F) . (G . d,(the_unity_wrt F))))
by A1, BINOP_1:def 3;
then
the_unity_wrt F = F . (G . d,(the_unity_wrt F)),(the_unity_wrt F)
by A1, A2, A3, Th63;
then
the_unity_wrt F = G . d,(the_unity_wrt F)
by A2, SETWISEO:23;
then
G . d,((id D) . (the_unity_wrt F)) = the_unity_wrt F
by FUNCT_1:35;
hence
(G [;] d,(id D)) . (the_unity_wrt F) = the_unity_wrt F
by FUNCOP_1:66; verum