let I be BinOp of [.0,1.]; for N being Fuzzy_Negation st I is satisfying_(I2) & I is N -satisfying_CP holds
I is satisfying_(I1)
let N be Fuzzy_Negation; ( I is satisfying_(I2) & I is N -satisfying_CP implies I is satisfying_(I1) )
assume that
A0:
I is satisfying_(I2)
and
AA:
I is N -satisfying_CP
; I is satisfying_(I1)
for x, y, z being Element of [.0,1.] st x <= y holds
I . (x,z) >= I . (y,z)
proof
let x,
y,
z be
Element of
[.0,1.];
( x <= y implies I . (x,z) >= I . (y,z) )
assume
x <= y
;
I . (x,z) >= I . (y,z)
then F0:
N . y <= N . x
by FUZIMPL3:7;
A3:
I . (
(N . z),
(N . x))
= I . (
x,
z)
by AA;
I . (
(N . z),
(N . x))
>= I . (
(N . z),
(N . y))
by F0, A0;
hence
I . (
x,
z)
>= I . (
y,
z)
by A3, AA;
verum
end;
hence
I is satisfying_(I1)
; verum