let it1, it2 be Element of D ^omega ; ( ex g being BinOp of (D ^omega ) st
( ( for p, q being Element of D ^omega holds g . p,q = p ^ q ) & it1 = g "**" F ) & ex g being BinOp of (D ^omega ) st
( ( for p, q being Element of D ^omega holds g . p,q = p ^ q ) & it2 = g "**" F ) implies it1 = it2 )
given g1 being BinOp of (D ^omega ) such that A2:
for p, q being Element of D ^omega holds g1 . p,q = p ^ q
and
A3:
it1 = g1 "**" F
; ( for g being BinOp of (D ^omega ) holds
( ex p, q being Element of D ^omega st not g . p,q = p ^ q or not it2 = g "**" F ) or it1 = it2 )
given g2 being BinOp of (D ^omega ) such that A4:
for p, q being Element of D ^omega holds g2 . p,q = p ^ q
and
A5:
it2 = g2 "**" F
; it1 = it2
hence
it1 = it2
by A3, A5, BINOP_1:2; verum