let I be BinOp of [.0,1.]; for N being negation-strict Fuzzy_Negation
for N1 being Fuzzy_Negation st N ~ = N1 holds
( I is N -satisfying_L-CP iff I is N1 -satisfying_R-CP )
let N be negation-strict Fuzzy_Negation; for N1 being Fuzzy_Negation st N ~ = N1 holds
( I is N -satisfying_L-CP iff I is N1 -satisfying_R-CP )
let N1 be Fuzzy_Negation; ( N ~ = N1 implies ( I is N -satisfying_L-CP iff I is N1 -satisfying_R-CP ) )
assume A0:
N ~ = N1
; ( I is N -satisfying_L-CP iff I is N1 -satisfying_R-CP )
then
N is onto
by LemmaOnto2;
then A2:
rng N = [.0,1.]
by FUNCT_2:def 3;
DD:
N " = N ~
by FUNCT_1:def 5;
thus
( I is N -satisfying_L-CP implies I is N1 -satisfying_R-CP )
( I is N1 -satisfying_R-CP implies I is N -satisfying_L-CP )proof
assume a1:
I is
N -satisfying_L-CP
;
I is N1 -satisfying_R-CP
for
x,
y being
Element of
[.0,1.] holds
I . (
x,
(N1 . y))
= I . (
y,
(N1 . x))
proof
let x,
y be
Element of
[.0,1.];
I . (x,(N1 . y)) = I . (y,(N1 . x))
I . (
x,
(N1 . y)) =
I . (
(N . (N1 . x)),
(N1 . y))
by A0, A2, FUNCT_1:35, DD
.=
I . (
(N . (N1 . y)),
(N1 . x))
by a1
.=
I . (
y,
(N1 . x))
by A2, DD, A0, FUNCT_1:35
;
hence
I . (
x,
(N1 . y))
= I . (
y,
(N1 . x))
;
verum
end;
hence
I is
N1 -satisfying_R-CP
;
verum
end;
assume a1:
I is N1 -satisfying_R-CP
; I is N -satisfying_L-CP
C1:
dom N = [.0,1.]
by FUNCT_2:def 1;
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)
B2:
(N1 * N) . y = y
by A0, C1, FUNCT_1:34, DD;
(N1 * N) . y = N1 . (N . y)
by C1, FUNCT_1:13;
then I . (
(N . x),
y) =
I . (
(N . y),
(N1 . (N . x)))
by a1, B2
.=
I . (
(N . y),
x)
by A0, C1, FUNCT_1:34, DD
;
hence
I . (
(N . x),
y)
= I . (
(N . y),
x)
;
verum
end;
hence
I is N -satisfying_L-CP
; verum