let o1, o2 be TriOp of REAL ; :: thesis: ( ( for a, b, c being Real holds o1 . a,b,c = (a * b) + c ) & ( for a, b, c being Real holds o2 . a,b,c = (a * b) + c ) implies o1 = o2 )
assume that
A1:
for a, b, c being Real holds o1 . a,b,c = (a * b) + c
and
A2:
for a, b, c being Real holds o2 . a,b,c = (a * b) + c
; :: thesis: o1 = o2
for a, b, c being Real holds o1 . a,b,c = o2 . a,b,c
proof
let a,
b,
c be
Real;
:: thesis: o1 . a,b,c = o2 . a,b,c
thus o1 . a,
b,
c =
(a * b) + c
by A1
.=
o2 . a,
b,
c
by A2
;
:: thesis: verum
end;
hence
o1 = o2
by MULTOP_1:4; :: thesis: verum