let I be Fuzzy_Implication; for f being bijective increasing UnOp of [.0,1.] st I is satisfying_(OP) holds
ConjImpl (I,f) is satisfying_(OP)
let f be bijective increasing UnOp of [.0,1.]; ( I is satisfying_(OP) implies ConjImpl (I,f) is satisfying_(OP) )
assume B0:
I is satisfying_(OP)
; ConjImpl (I,f) is satisfying_(OP)
set g = ConjImpl (I,f);
let x, y be Element of [.0,1.]; FUZIMPL2:def 4 ( ( not (ConjImpl (I,f)) . (x,y) = 1 or x <= y ) & ( not x <= y or (ConjImpl (I,f)) . (x,y) = 1 ) )
b3:
rng f = [.0,1.]
by FUNCT_2:def 3;
b4:
dom f = [.0,1.]
by FUNCT_2:def 1;
thus
( (ConjImpl (I,f)) . (x,y) = 1 implies x <= y )
( not x <= y or (ConjImpl (I,f)) . (x,y) = 1 )
assume
x <= y
; (ConjImpl (I,f)) . (x,y) = 1
then
f . x <= f . y
by Rosnie;
then
I . ((f . x),(f . y)) = 1
by FUZIMPL2:def 4, B0;
then
(f ") . (I . ((f . x),(f . y))) = 1
by LemmaBound;
hence
(ConjImpl (I,f)) . (x,y) = 1
by BIDef; verum