let w1, w2 be BinOp of (n -tuples_on the carrier of R); ( ( for u, v being Tuple of n, the carrier of R holds w1 . (u,v) = u + v ) & ( for u, v being Tuple of n, the carrier of R holds w2 . (u,v) = u + v ) implies w1 = w2 )
assume that
A1:
for u, v being Tuple of n, the carrier of R holds w1 . (u,v) = u + v
and
A2:
for u, v being Tuple of n, the carrier of R holds w2 . (u,v) = u + v
; w1 = w2
hence
w1 = w2
by FUNCT_2:12; verum