let I be BinOp of [.0,1.]; for N being negation-strong Fuzzy_Negation st I is N -satisfying_R-CP holds
I is N -satisfying_CP
let N be negation-strong Fuzzy_Negation; ( I is N -satisfying_R-CP implies I is N -satisfying_CP )
assume a0:
I is N -satisfying_R-CP
; I is N -satisfying_CP
d1:
N is involutive
by FUZIMPL3:def 11, FUZIMPL3:def 13;
for x, y being Element of [.0,1.] holds I . (x,y) = I . ((N . y),(N . x))
proof
let x,
y be
Element of
[.0,1.];
I . (x,y) = I . ((N . y),(N . x))
I . (
x,
y) =
I . (
x,
(N . (N . y)))
by d1, FUZIMPL3:def 8
.=
I . (
(N . y),
(N . x))
by a0
;
hence
I . (
x,
y)
= I . (
(N . y),
(N . x))
;
verum
end;
hence
I is N -satisfying_CP
; verum