let X be non empty set ; :: thesis: for R, R' being RMembership_Func of X,X st R' is symmetric & R c= holds
min R,(converse R) c=
let R, T be RMembership_Func of X,X; :: thesis: ( T is symmetric & R c= implies min R,(converse R) c= )
assume A1:
( T is symmetric & R c= )
; :: thesis: min R,(converse R) c=
let x, y be Element of X; :: according to LFUZZY_1:def 1 :: thesis: T . x,y <= (min R,(converse R)) . x,y
A2:
( T . [x,y] <= R . [x,y] & T . [y,x] <= R . [y,x] )
by A1, FUZZY_1:def 3;
then
( T . x,y <= R . x,y & T . y,x <= R . y,x )
;
then
T . x,y <= R . y,x
by A1, Def5;
then
T . x,y <= min (R . x,y),(R . y,x)
by A2, XXREAL_0:20;
then
T . x,y <= min (R . x,y),((converse R) . x,y)
by FUZZY_4:26;
then
T . [x,y] <= min (R . [x,y]),((converse R) . [x,y])
;
hence
T . x,y <= (min R,(converse R)) . x,y
by FUZZY_1:def 4; :: thesis: verum