let S be 1-sorted ; :: thesis: for A being ManySortedSet of the carrier of S
for J being MSClosureOperator of A holds ClSys->ClOp (ClOp->ClSys J) = J

let A be ManySortedSet of the carrier of S; :: thesis: for J being MSClosureOperator of A holds ClSys->ClOp (ClOp->ClSys J) = J
let J be MSClosureOperator of A; :: thesis: ClSys->ClOp (ClOp->ClSys J) = J
set I = the carrier of S;
set M = the Sorts of (ClOp->ClSys J);
set j = ClSys->ClOp (ClOp->ClSys J);
consider D being MSSubsetFamily of A such that
A1: D = MSFixPoints J and
A2: ClOp->ClSys J = MSClosureStr(# A,D #) by Def14;
A3: the Family of (ClOp->ClSys J) = D by A2;
for X being ManySortedSet of the carrier of S st X in bool A holds
(ClSys->ClOp (ClOp->ClSys J)) .. X = J .. X
proof
let X be ManySortedSet of the carrier of S; :: thesis: ( X in bool A implies (ClSys->ClOp (ClOp->ClSys J)) .. X = J .. X )
assume X in bool A ; :: thesis: (ClSys->ClOp (ClOp->ClSys J)) .. X = J .. X
then A4: X is Element of bool the Sorts of (ClOp->ClSys J) by A2, MSSUBFAM:11;
then consider SF being V8 MSSubsetFamily of the Sorts of (ClOp->ClSys J) such that
A5: for Y being ManySortedSet of the carrier of S holds
( Y in SF iff ( Y in MSFixPoints J & X c= Y ) ) by A1, A3, Th31;
now
let i be set ; :: thesis: ( i in the carrier of S implies ((ClSys->ClOp (ClOp->ClSys J)) .. X) . i = (J .. X) . i )
assume A6: i in the carrier of S ; :: thesis: ((ClSys->ClOp (ClOp->ClSys J)) .. X) . i = (J .. X) . i
A7: dom J = the carrier of S by PBOOLE:def 3;
reconsider f = J . i as Function of (bool A) . i,(bool A) . i by A6, PBOOLE:def 18;
(bool A) . i = bool (A . i) by A6, MBOOLEAN:def 1;
then reconsider f = f as Function of bool (A . i), bool (A . i) ;
consider Q being Subset-Family of (the Sorts of (ClOp->ClSys J) . i) such that
A8: Q = SF . i and
A9: (meet SF) . i = Intersect Q by A6, MSSUBFAM:def 2;
reconsider Di = (MSFixPoints J) . i as non empty set by A1, A3, A6;
Intersect Q = f . (X . i)
proof
A10: SF . i = { z where z is Element of Di : X . i c= z } by A1, A3, A4, A5, A6, Th32;
X . i is Element of (bool A) . i by A2, A4, A6, PBOOLE:def 17;
then A11: X . i is Element of bool (A . i) by A6, MBOOLEAN:def 1;
A12: dom f = bool (A . i) by FUNCT_2:def 1;
A13: f . (X . i) in bool (A . i) by A11, FUNCT_2:7;
f . (f . (X . i)) = f . (X . i) by A6, A11, Th26;
then A14: f . (X . i) is Element of Di by A6, A12, A13, Def13;
X . i c= f . (X . i) by A6, A11, Th24;
then f . (X . i) in { z where z is Element of Di : X . i c= z } by A14;
hence Intersect Q c= f . (X . i) by A8, A10, MSSUBFAM:2; :: according to XBOOLE_0:def 10 :: thesis: f . (X . i) c= Intersect Q
A15: Q <> {} by A6, A8;
now
let x be set ; :: thesis: ( x in Q implies f . (X . i) c= x )
assume x in Q ; :: thesis: f . (X . i) c= x
then consider x1 being Element of Di such that
A16: ( x1 = x & X . i c= x1 ) by A8, A10;
MSFixPoints J c= bool A by PBOOLE:def 23;
then Di c= (bool A) . i by A6, PBOOLE:def 5;
then Di c= bool (A . i) by A6, MBOOLEAN:def 1;
then A17: x1 is Element of bool (A . i) by TARSKI:def 3;
consider g being Function such that
A18: ( g = J . i & x1 in dom g & g . x1 = x1 ) by A6, Def13;
thus f . (X . i) c= x by A6, A11, A16, A17, A18, Th25; :: thesis: verum
end;
hence f . (X . i) c= Intersect Q by A15, MSSUBFAM:5; :: thesis: verum
end;
hence ((ClSys->ClOp (ClOp->ClSys J)) .. X) . i = f . (X . i) by A1, A2, A4, A5, A9, Def15
.= (J .. X) . i by A6, A7, PRALG_1:def 17 ;
:: thesis: verum
end;
hence (ClSys->ClOp (ClOp->ClSys J)) .. X = J .. X by PBOOLE:3; :: thesis: verum
end;
hence ClSys->ClOp (ClOp->ClSys J) = J by A2, Th7; :: thesis: verum