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