let F1, F2 be BinOp of (carr (x,o)); ( ( for a, b being Element of carr (x,o) holds F1 . (a,b) = multR (a,b) ) & ( for a, b being Element of carr (x,o) holds F2 . (a,b) = multR (a,b) ) implies F1 = F2 )
assume that
A2:
for a, b being Element of carr (x,o) holds F1 . (a,b) = multR (a,b)
and
A3:
for a, b being Element of carr (x,o) holds F2 . (a,b) = multR (a,b)
; F1 = F2
hence
F1 = F2
by BINOP_1:2; verum