let C1, C2, C3 be non empty set ; :: thesis: for f being RMembership_Func of C1,C2
for g, h being RMembership_Func of C2,C3
for x, z being set st x in C1 & z in C3 holds
sup (rng (min f,(max g,h),x,z)) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))

let f be RMembership_Func of C1,C2; :: thesis: for g, h being RMembership_Func of C2,C3
for x, z being set st x in C1 & z in C3 holds
sup (rng (min f,(max g,h),x,z)) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))

let g, h be RMembership_Func of C2,C3; :: thesis: for x, z being set st x in C1 & z in C3 holds
sup (rng (min f,(max g,h),x,z)) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))

let x, z be set ; :: thesis: ( x in C1 & z in C3 implies sup (rng (min f,(max g,h),x,z)) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) )
assume A1: ( x in C1 & z in C3 ) ; :: thesis: sup (rng (min f,(max g,h),x,z)) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))
A2: ( dom (max (min f,g,x,z),(min f,h,x,z)) = C2 & dom (min f,(max g,h),x,z) = C2 ) by FUNCT_2:def 1;
A3: for y being Element of C2 st y in C2 holds
(max (min f,g,x,z),(min f,h,x,z)) . y = (min f,(max g,h),x,z) . y
proof
let y be Element of C2; :: thesis: ( y in C2 implies (max (min f,g,x,z),(min f,h,x,z)) . y = (min f,(max g,h),x,z) . y )
assume y in C2 ; :: thesis: (max (min f,g,x,z),(min f,h,x,z)) . y = (min f,(max g,h),x,z) . y
A4: [y,z] in [:C2,C3:] by A1, ZFMISC_1:106;
(max (min f,g,x,z),(min f,h,x,z)) . y = max ((min f,g,x,z) . y),((min f,h,x,z) . y) by FUZZY_1:def 5
.= max ((min f,g,x,z) . y),(min (f . [x,y]),(h . [y,z])) by A1, Def2
.= max (min (f . [x,y]),(g . [y,z])),(min (f . [x,y]),(h . [y,z])) by A1, Def2
.= min (f . [x,y]),(max (g . [y,z]),(h . [y,z])) by XXREAL_0:38
.= min (f . [x,y]),((max g,h) . [y,z]) by A4, FUZZY_1:def 5
.= (min f,(max g,h),x,z) . y by A1, Def2 ;
hence (max (min f,g,x,z),(min f,h,x,z)) . y = (min f,(max g,h),x,z) . y ; :: thesis: verum
end;
set F = min f,g,x,z;
set G = min f,h,x,z;
sup (rng (max (min f,g,x,z),(min f,h,x,z))) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))
proof
A5: sup (rng (max (min f,g,x,z),(min f,h,x,z))) <= max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))
proof
rng (max (min f,g,x,z),(min f,h,x,z)) is bounded by Th1;
then A6: rng (max (min f,g,x,z),(min f,h,x,z)) is bounded_above by XXREAL_2:def 11;
A7: for s being real number st 0 < s holds
ex y being set st
( y in dom (max (min f,g,x,z),(min f,h,x,z)) & (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y )
proof
let s be real number ; :: thesis: ( 0 < s implies ex y being set st
( y in dom (max (min f,g,x,z),(min f,h,x,z)) & (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y ) )

assume 0 < s ; :: thesis: ex y being set st
( y in dom (max (min f,g,x,z),(min f,h,x,z)) & (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y )

then consider r being real number such that
A8: ( r in rng (max (min f,g,x,z),(min f,h,x,z)) & (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < r ) by A6, SEQ_4:def 4;
consider y being set such that
A9: ( y in dom (max (min f,g,x,z),(min f,h,x,z)) & r = (max (min f,g,x,z),(min f,h,x,z)) . y ) by A8, FUNCT_1:def 5;
thus ex y being set st
( y in dom (max (min f,g,x,z),(min f,h,x,z)) & (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y ) by A8, A9; :: thesis: verum
end;
for s being real number st 0 < s holds
(sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))
proof
let s be real number ; :: thesis: ( 0 < s implies (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) )
assume 0 < s ; :: thesis: (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z)))
then consider y being set such that
A10: ( y in dom (max (min f,g,x,z),(min f,h,x,z)) & (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y ) by A7;
A11: (max (min f,g,x,z),(min f,h,x,z)) . y = max ((min f,g,x,z) . y),((min f,h,x,z) . y) by A10, FUZZY_1:def 5;
( (min f,g,x,z) . y <= sup (rng (min f,g,x,z)) & (min f,h,x,z) . y <= sup (rng (min f,h,x,z)) )
proof
for y being set st y in C2 holds
( (min f,g,x,z) . y <= sup (rng (min f,g,x,z)) & (min f,h,x,z) . y <= sup (rng (min f,h,x,z)) )
proof
let y be set ; :: thesis: ( y in C2 implies ( (min f,g,x,z) . y <= sup (rng (min f,g,x,z)) & (min f,h,x,z) . y <= sup (rng (min f,h,x,z)) ) )
assume y in C2 ; :: thesis: ( (min f,g,x,z) . y <= sup (rng (min f,g,x,z)) & (min f,h,x,z) . y <= sup (rng (min f,h,x,z)) )
then ( y in dom (min f,g,x,z) & y in dom (min f,h,x,z) ) by FUNCT_2:def 1;
then A12: ( (min f,g,x,z) . y in rng (min f,g,x,z) & (min f,h,x,z) . y in rng (min f,h,x,z) ) by FUNCT_1:def 5;
( rng (min f,g,x,z) is bounded & rng (min f,h,x,z) is bounded ) by Th1;
then ( rng (min f,g,x,z) is bounded_above & rng (min f,h,x,z) is bounded_above ) by XXREAL_2:def 11;
hence ( (min f,g,x,z) . y <= sup (rng (min f,g,x,z)) & (min f,h,x,z) . y <= sup (rng (min f,h,x,z)) ) by A12, SEQ_4:def 4; :: thesis: verum
end;
hence ( (min f,g,x,z) . y <= sup (rng (min f,g,x,z)) & (min f,h,x,z) . y <= sup (rng (min f,h,x,z)) ) by A10; :: thesis: verum
end;
then (max (min f,g,x,z),(min f,h,x,z)) . y <= max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) by A11, XXREAL_0:26;
hence (sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s < max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) by A10, XXREAL_0:2; :: thesis: verum
end;
then for s being real number st 0 < s holds
(sup (rng (max (min f,g,x,z),(min f,h,x,z)))) - s <= max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) ;
hence sup (rng (max (min f,g,x,z),(min f,h,x,z))) <= max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) by XREAL_1:59; :: thesis: verum
end;
A13: for y being set st y in C2 holds
(max (min f,g,x,z),(min f,h,x,z)) . y <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
proof
let y be set ; :: thesis: ( y in C2 implies (max (min f,g,x,z),(min f,h,x,z)) . y <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) )
assume y in C2 ; :: thesis: (max (min f,g,x,z),(min f,h,x,z)) . y <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
then y in dom (max (min f,g,x,z),(min f,h,x,z)) by FUNCT_2:def 1;
then A14: (max (min f,g,x,z),(min f,h,x,z)) . y in rng (max (min f,g,x,z),(min f,h,x,z)) by FUNCT_1:def 5;
rng (max (min f,g,x,z),(min f,h,x,z)) is bounded by Th1;
then rng (max (min f,g,x,z),(min f,h,x,z)) is bounded_above by XXREAL_2:def 11;
hence (max (min f,g,x,z),(min f,h,x,z)) . y <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by A14, SEQ_4:def 4; :: thesis: verum
end;
max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
proof
A15: sup (rng (min f,g,x,z)) <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
proof
rng (min f,g,x,z) is bounded by Th1;
then A16: rng (min f,g,x,z) is bounded_above by XXREAL_2:def 11;
A17: for s being real number st 0 < s holds
ex y being set st
( y in dom (min f,g,x,z) & (sup (rng (min f,g,x,z))) - s < (min f,g,x,z) . y )
proof
let s be real number ; :: thesis: ( 0 < s implies ex y being set st
( y in dom (min f,g,x,z) & (sup (rng (min f,g,x,z))) - s < (min f,g,x,z) . y ) )

assume 0 < s ; :: thesis: ex y being set st
( y in dom (min f,g,x,z) & (sup (rng (min f,g,x,z))) - s < (min f,g,x,z) . y )

then consider r being real number such that
A18: ( r in rng (min f,g,x,z) & (sup (rng (min f,g,x,z))) - s < r ) by A16, SEQ_4:def 4;
consider y being set such that
A19: ( y in dom (min f,g,x,z) & r = (min f,g,x,z) . y ) by A18, FUNCT_1:def 5;
thus ex y being set st
( y in dom (min f,g,x,z) & (sup (rng (min f,g,x,z))) - s < (min f,g,x,z) . y ) by A18, A19; :: thesis: verum
end;
for s being real number st 0 < s holds
(sup (rng (min f,g,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
proof
let s be real number ; :: thesis: ( 0 < s implies (sup (rng (min f,g,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) )
assume 0 < s ; :: thesis: (sup (rng (min f,g,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
then consider y being set such that
A20: ( y in dom (min f,g,x,z) & (sup (rng (min f,g,x,z))) - s < (min f,g,x,z) . y ) by A17;
(min f,g,x,z) . y <= max ((min f,g,x,z) . y),((min f,h,x,z) . y) by XXREAL_0:25;
then (min f,g,x,z) . y <= (max (min f,g,x,z),(min f,h,x,z)) . y by A20, FUZZY_1:def 5;
then A21: (sup (rng (min f,g,x,z))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y by A20, XXREAL_0:2;
(max (min f,g,x,z),(min f,h,x,z)) . y <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by A13, A20;
hence (sup (rng (min f,g,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by A21, XXREAL_0:2; :: thesis: verum
end;
hence sup (rng (min f,g,x,z)) <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by XREAL_1:59; :: thesis: verum
end;
sup (rng (min f,h,x,z)) <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
proof
rng (min f,h,x,z) is bounded by Th1;
then A22: rng (min f,h,x,z) is bounded_above by XXREAL_2:def 11;
A23: for s being real number st 0 < s holds
ex y being set st
( y in dom (min f,h,x,z) & (sup (rng (min f,h,x,z))) - s < (min f,h,x,z) . y )
proof
let s be real number ; :: thesis: ( 0 < s implies ex y being set st
( y in dom (min f,h,x,z) & (sup (rng (min f,h,x,z))) - s < (min f,h,x,z) . y ) )

assume 0 < s ; :: thesis: ex y being set st
( y in dom (min f,h,x,z) & (sup (rng (min f,h,x,z))) - s < (min f,h,x,z) . y )

then consider r being real number such that
A24: ( r in rng (min f,h,x,z) & (sup (rng (min f,h,x,z))) - s < r ) by A22, SEQ_4:def 4;
consider y being set such that
A25: ( y in dom (min f,h,x,z) & r = (min f,h,x,z) . y ) by A24, FUNCT_1:def 5;
thus ex y being set st
( y in dom (min f,h,x,z) & (sup (rng (min f,h,x,z))) - s < (min f,h,x,z) . y ) by A24, A25; :: thesis: verum
end;
for s being real number st 0 < s holds
(sup (rng (min f,h,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
proof
let s be real number ; :: thesis: ( 0 < s implies (sup (rng (min f,h,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) )
assume 0 < s ; :: thesis: (sup (rng (min f,h,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z)))
then consider y being set such that
A26: ( y in dom (min f,h,x,z) & (sup (rng (min f,h,x,z))) - s < (min f,h,x,z) . y ) by A23;
(min f,h,x,z) . y <= max ((min f,g,x,z) . y),((min f,h,x,z) . y) by XXREAL_0:25;
then (min f,h,x,z) . y <= (max (min f,g,x,z),(min f,h,x,z)) . y by A26, FUZZY_1:def 5;
then A27: (sup (rng (min f,h,x,z))) - s < (max (min f,g,x,z),(min f,h,x,z)) . y by A26, XXREAL_0:2;
(max (min f,g,x,z),(min f,h,x,z)) . y <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by A13, A26;
hence (sup (rng (min f,h,x,z))) - s <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by A27, XXREAL_0:2; :: thesis: verum
end;
hence sup (rng (min f,h,x,z)) <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by XREAL_1:59; :: thesis: verum
end;
hence max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) <= sup (rng (max (min f,g,x,z),(min f,h,x,z))) by A15, XXREAL_0:28; :: thesis: verum
end;
hence sup (rng (max (min f,g,x,z),(min f,h,x,z))) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) by A5, XXREAL_0:1; :: thesis: verum
end;
hence sup (rng (min f,(max g,h),x,z)) = max (sup (rng (min f,g,x,z))),(sup (rng (min f,h,x,z))) by A2, A3, PARTFUN1:34; :: thesis: verum