The Mizar article:

Transitive Closure of Fuzzy Relations

by
Takashi Mitsuishi, and
Grzegorz Bancerek

Received November 23, 2003

Copyright (c) 2003 Association of Mizar Users

MML identifier: LFUZZY_1
[ MML identifier index ]


environ

 vocabulary LFUZZY_0, ARYTM, RELAT_2, LATTICES, RCOMP_1, FUNCT_1, RELAT_1,
      QC_LANG1, FUZZY_3, SEQ_1, FUZZY_1, GROUP_1, LATTICE2, LATTICE3, WAYBEL_0,
      SQUARE_1, BOOLE, SEQ_4, BHSP_3, ORDINAL2, FUNCT_2, PARTFUN1, FUNCT_4,
      CARD_3, WAYBEL_1, FUNCOP_1, FUZZY_4, FUNCT_3, LFUZZY_1;
 notation TARSKI, XBOOLE_0, ZFMISC_1, RELAT_1, FUNCT_1, FUNCT_2, ORDINAL1,
      ORDINAL2, NUMBERS, XCMPLX_0, DOMAIN_1, PARTFUN1, CARD_3, RELAT_2,
      FUNCT_3, RFUNCT_1, SUBSET_1, XREAL_0, NAT_1, SQUARE_1, SEQ_1, SEQ_4,
      RCOMP_1, RELSET_1, STRUCT_0, LATTICE3, YELLOW_0, WAYBEL_0, YELLOW_1,
      WAYBEL_1, WAYBEL_3, FUZZY_1, FUZZY_3, FUZZY_4, PRE_CIRC, LFUZZY_0;
 constructors NAT_1, WAYBEL_2, PSCOMP_1, WAYBEL_3, FUZZY_4, DOMAIN_1, ORDERS_3,
      PRE_CIRC, FUZZY_3, MONOID_0, LFUZZY_0, RFUNCT_1, REAL_1;
 clusters SUBSET_1, LATTICE3, RELSET_1, STRUCT_0, MONOID_0, SEQ_1, NAT_1,
      ORDINAL2, WAYBEL_2, WAYBEL10, WAYBEL17, LFUZZY_0, INT_1, MEMBERED,
      BINARITH;
 requirements BOOLE, SUBSET, NUMERALS, REAL, ARITHM;
 definitions TARSKI, XBOOLE_0;
 theorems ZFMISC_1, WAYBEL_1, AXIOMS, RELAT_1, LATTICE3, SQUARE_1, YELLOW_0,
      XREAL_0, TARSKI, TOPMETR3, YELLOW_2, WAYBEL_3, CARD_3, YELLOW_1,
      FUNCOP_1, FUZZY_2, FUZZY_4, FUNCT_3, FUZZY_1, PARTFUN1, LFUZZY_0,
      RELAT_2, ORDINAL2, XCMPLX_1, ANALOAF;
 schemes FRAENKEL, RECDEF_1, NAT_1, LFUZZY_0, BINARITH;

begin :: Inclusion of fuzzy relations

 reserve X, Y, Z for non empty set;

Th7:
for a,b,c,d being real number st a <= b & c <= d holds min(a,c) <= min(b,d)
  proof
   let a,b,c,d be real number;
   assume 
A1:a <= b & c <= d;
   reconsider a,b,c,d as Element of REAL by XREAL_0:def 1;
   a <= b & c <= d by A1;
   hence thesis by FUZZY_1:44;
  end;

definition
  let X be non empty set;
  cluster -> real-yielding Membership_Func of X;
  coherence;
end;

definition
  let f,g be real-yielding Function;
  pred f is_less_than g means:Def0:
   dom f c= dom g &
   for x being set st x in dom f holds f.x <= g.x;   
end;

definition
 let X be non empty set;
 let f,g be Membership_Func of X;
 redefine pred f is_less_than g means :Def1:
  for x being Element of X holds f.x <= g.x;
  compatibility
  proof
   thus f is_less_than g iff for x being Element of X holds f.x <= g.x
    proof
     hereby assume
AA:     f is_less_than g;
     thus for x being Element of X holds f.x <= g.x 
      proof
       let x be Element of X;
       dom f = X by FUZZY_1:def 1;      
       hence thesis by AA,Def0;
      end;
     end;
     assume 
A4:  for x being Element of X holds f.x <= g.x;
A3:  dom f = X & dom g = X by FUZZY_1:def 1;
     for x being set st x in dom f holds f.x <= g.x by A4;
     hence f is_less_than g by A3,Def0;
    end;
  end;
  synonym f c= g;
end;

definition                        
 let X,Y be non empty set;
 let f,g be RMembership_Func of X,Y;
 redefine pred f is_less_than g means :Def2:
  for x being Element of X, y being Element of Y holds f. [x,y] <= g. [x,y];
  compatibility
  proof
   thus f is_less_than g iff
   for x being Element of X, y being Element of Y holds f. [x,y] <= g. [x,y]
    proof
     hereby assume
AA:  f is_less_than g;
     thus
     for x being Element of X, y being Element of Y holds f. [x,y] <= g. [x,y]
      proof
       let x be Element of X, y be Element of Y;
       dom f = [:X,Y:] & [x,y] in [:X,Y:] by FUZZY_1:def 1;
       hence thesis by AA,Def0;
      end;
     end;
     assume 
 A4: for x being Element of X, y being Element of Y holds f. [x,y] <= g. [x,y];
 A3: dom f = [:X,Y:] & dom g = [:X,Y:] by FUZZY_1:def 1;
     for c being set st c in dom f holds f.c <= g.c
      proof
       let c be set;
       assume
 A:    c in dom f;
       consider x,y being set such that  
 A6:   [x,y] = c by A, ZFMISC_1:102;
       reconsider x as Element of X by ZFMISC_1:106,A6,A;
       reconsider y as Element of Y by ZFMISC_1:106,A6,A;
       f. [x,y] <= g. [x,y] by A4;
       hence thesis by A6;
      end;
     hence f is_less_than g by Def0,A3;
    end;
  end;
end;

theorem Th1_0:
  for R,S being Membership_Func of X 
   st for x being Element of X holds R.x = S.x
   holds R = S
    proof
      let R,S be Membership_Func of X;
      assume
A5:   for x being Element of X holds R.x = S.x;
A4:   dom R = X & dom S = X by FUZZY_1:def 1;
      for x being Element of X st x in dom R holds R.x = S.x by A5;
      hence R = S by A4,PARTFUN1:34;
    end; 

theorem Th1:
for R,S being RMembership_Func of X,Y
 st for x being Element of X, y being Element of Y holds R. [x,y] = S. [x,y]
 holds R = S
  proof
   let R,S be RMembership_Func of X,Y;
   assume
A5:for x being Element of X, y being Element of Y holds R. [x,y] = S. [x,y];
A4:dom R = [:X,Y:] & dom S = [:X,Y:] by FUZZY_1:def 1;
   for x,y being set st [x,y] in dom R holds R. [x,y] = S. [x,y]
    proof
     let x,y be set;
     assume
Z1:     [x,y] in dom R;
     reconsider x as Element of X by Z1, ZFMISC_1:106;
     reconsider y as Element of Y by Z1, ZFMISC_1:106;
     R. [x,y] = S. [x,y] by A5;
     hence thesis;
    end;
   hence R = S by A4,PARTFUN1:35;
  end; 

theorem FUZZY13:
  for R,S being Membership_Func of X holds
  R = S iff R c= S & S c= R
    proof
      let R,S be Membership_Func of X;
      hereby assume R=S;then
        for x being Element of X holds R.x <= S.x & S.x <= R.x;
        hence R c= S & S c= R by Def1;
      end;
      assume
AS:   R c= S & S c= R;
      for x being Element of X holds R.x = S.x
        proof
          let x be Element of X;
          R.x <R= S.x & S.x <R= R.x by AS,Def1;
          hence thesis by AXIOMS:21;
        end;
      hence R=S by Th1_0;
    end;

theorem FUZZY14:
  for R being Membership_Func of X holds
  R c= R
    proof
      let R be Membership_Func of X;
      for x being Element of X holds R.x <= R.x;
      hence thesis by Def1;
    end;

theorem FUZZY15:
  for R,S,T being Membership_Func of X holds
  R c= S & S c= T implies R c= T
    proof
      let R,S,T be Membership_Func of X;
      assume
A1:   R c= S & S c= T;
      for x being Element of X holds R.x <= T.x
        proof
          let x be Element of X;
          R.x <R= S.x & S.x <R= T.x by A1,Def1;
          hence thesis by AXIOMS:22;
        end;
      hence thesis by Def1;
    end;

theorem FUZZY430:
  for X,Y,Z being non empty set,
  R,S being RMembership_Func of X,Y, T,U being RMembership_Func of Y,Z
  holds R c= S & T c= U implies R(#)T c= S(#)U
    proof
      let X,Y,Z be non empty set;
      let R,S be RMembership_Func of X,Y;
      let T,U be RMembership_Func of Y,Z;
      assume
AS:   R c= S & T c= U;
      for c being Element of [:X,Z:] holds (R(#)T).c <= (S(#)U).c
        proof
          let c be Element of [:X,Z:];
          consider x,z being set such that 
A3:       [x,z] = c by ZFMISC_1:102;
A1:       x in X & z in Z by ZFMISC_1:106,A3;
          for y be set st y in Y holds
          R. [x,y] <= S. [x,y] & T. [y,z] <= U. [y,z]
            proof
              let y be set; assume
              y in Y; then
              [x,y] in [:X,Y:] & [y,z] in [:Y,Z:] by A1,ZFMISC_1:106;
              hence thesis by AS,Def1;
            end;
          hence thesis by A3,FUZZY_4:29,A1;
        end;
      hence thesis by Def1;
    end;

definition
  let X be non empty set;
  let f,g be Membership_Func of X;
  redefine func min(f,g);
  commutativity by FUZZY_1:7;
  redefine func max(f,g);
  commutativity by FUZZY_1:7;
end;

theorem
 for f,g being Membership_Func of X holds min(f,g) c= f
  proof let f,g be Membership_Func of X;
    let x be Element of X;
    min(f,g).x = min(f.x,g.x) by FUZZY_1:def 5;
    hence min(f,g).x <= f.x by SQUARE_1:35;
  end;

theorem
 for f,g being Membership_Func of X holds f c= max(f,g)
  proof let f,g be Membership_Func of X;
    let x be Element of X;
    max(f,g).x = max(f.x,g.x) by FUZZY_1:def 6;
    hence thesis by SQUARE_1:46;
  end;

begin :: Properties of fuzzy relations

definition
  let X be non empty set;
  let R be RMembership_Func of X,X;
  attr R is reflexive means:Def3:
   Imf(X,X) c= R;
end;

definition
 let X be non empty set;
 let R be RMembership_Func of X,X;
 redefine attr R is reflexive means :Def4:
  for x being Element of X holds R. [x,x] = 1;
 compatibility
 proof
  thus R is reflexive iff for x being Element of X holds R. [x,x] = 1
   proof
    hereby assume R is reflexive;then
A3:    Imf(X,X) c= R by Def3;
    thus for x being Element of X holds R. [x,x] = 1
     proof
      let x be Element of X;
      Imf(X,X). [x,x] <= R. [x,x] & Imf(X,X). [x,x] = 1 
        by Def2,A3,FUZZY_4:def 6;
      then
      R. [x,x] <= 1 & R. [x,x] >= 1 by FUZZY_4:4;
      hence thesis by AXIOMS:21;
     end;
    end;
    assume 
A0: for x being Element of X holds R. [x,x] = 1;
    for x,y being Element of X holds Imf(X,X). [x,y] <= R. [x,y]
       proof
        let x,y be Element of X;
        per cases;
        suppose 
A1:     x = y;
A2:     Imf(X,X). [x,y] = 1 by A1,FUZZY_4:def 6;
        thus thesis by A1,A2,A0;
        suppose not x=y;then
        Imf(X,X). [x,y] = 0 by FUZZY_4:def 6;    
        hence thesis by FUZZY_4:4;    
       end;
      then Imf(X,X) c= R by Def2;
     hence R is reflexive by Def3;
   end;
 end;
end;

definition
 let X be non empty set;
 let R be RMembership_Func of X,X;
 attr R is symmetric means :Def5:
  converse R = R;
end;

definition
 let X be non empty set;
 let R be RMembership_Func of X,X;
 redefine attr R is symmetric means :Def6:
  for x,y being Element of X holds R. [x,y] = R. [y,x];
 compatibility
  proof
   thus R is symmetric iff for x,y being Element of X holds R. [x,y] = R. [y,x]
    proof
   hereby assume R is symmetric;then
   converse R = R by Def5;
   hence for x,y being Element of X holds R. [x,y] = R. [y,x]
   by FUZZY_4:def 1;
   end;      
   assume 
A3:for x,y being Element of X holds R. [x,y] = R. [y,x];
A4:dom converse R = [:X,X:] & dom R = [:X,X:] by FUZZY_1:def 1;
   for x,y being set st [x,y] in dom R holds (converse R). [x,y] = R. [x,y]
    proof
     let x,y be set;
     assume [x,y] in dom R;then
     reconsider x,y as Element of X by ZFMISC_1:106;
     R. [x,y] = R. [y,x] by A3;
     hence thesis by FUZZY_4:def 1;
    end;
    then converse R = R by PARTFUN1:35,A4;
    hence R is symmetric by Def5;
    end;
  end;
end;

definition
 let X be non empty set;
 let R be RMembership_Func of X,X;
 attr R is transitive means :Def7:
  R (#) R c= R;
end;

Th2:
  for X,Y,Z being non empty set
  for R being RMembership_Func of X,Y
  for S being RMembership_Func of Y,Z
  for x being Element of X, z being Element of Z
   holds  
   rng min(R,S,x,z) =
         {R. [x,y] "/\" S. [y,z] where y is Element of Y: not contradiction} &
   rng min(R,S,x,z) <> {}
    proof
     let X,Y,Z be non empty set;
     let R be RMembership_Func of X,Y;
     let S be RMembership_Func of Y,Z;
     let x be Element of X, z being Element of Z;
C2:  Y = dom min(R,S,x,z)
     & min(R,S,x,z) is PartFunc of dom min(R,S,x,z), rng min(R,S,x,z)
        by FUZZY_1:def 1, PARTFUN1:24;
     set L
     = {R. [x,y] "/\" S. [y,z] where y is Element of Y: not contradiction};
     for c be set holds c in L iff c in rng min(R,S,x,z)
      proof
       let c be set;
       hereby assume c in L;then
       consider y being Element of Y such that
C9:    c = R. [x,y] "/\" S. [y,z];
       c   = min(R. [x,y], S. [y,z] qua real number) by LFUZZY_0:5,C9
        .= min(R,S,x,z).y by FUZZY_4:def 3;          
       hence c in rng min(R,S,x,z) by C2,PARTFUN1:27;
       end;
       assume c in rng min(R,S,x,z);then
       consider y being Element of Y such that
C3:    y in dom min(R,S,x,z) & c = min(R,S,x,z).y by PARTFUN1:26;
       c = min(R. [x,y], S. [y,z] qua real number) by FUZZY_4:def 3,C3
        .= R. [x,y] "/\" S. [y,z] by LFUZZY_0:5;
       hence c in L;
      end;
     hence rng min(R,S,x,z) = L by TARSKI:2;
     thus rng min(R,S,x,z) <> {}
       proof
        ex d be set st d in rng min(R,S,x,z)
         proof
          consider y being Element of Y;
          take d = min(R,S,x,z).y;
          thus d in rng min(R,S,x,z) by C2,PARTFUN1:27;
         end;
        hence thesis;
       end;
    end;    

definition
 let X be non empty set;
 let R be RMembership_Func of X,X;
 redefine attr R is transitive means
  for x,y,z being Element of X holds R. [x,y] "/\" R. [y,z] <<= R. [x,z];
 compatibility
  proof
   thus R is transitive iff 
   for x,y,z being Element of X holds R. [x,y] "/\" R. [y,z] <<= R. [x,z]
    proof
     hereby assume
     R is transitive;then
AS:     R (#) R c= R by Def7;
     thus 
     for x,y,z being Element of X holds R. [x,y] "/\" R. [y,z] <<= R. [x,z]
      proof
       let x,y,z be Element of X;       
       R. [x,y] "/\" R. [y,z] in {R. [x,y'] "/\" R. [y',z] 
         where y' is Element of X: not contradiction};then
       R. [x,y] "/\" R. [y,z] <<= 
         "\/"({R. [x,y'] "/\" R. [y',z] where y' is Element of X: 
           not contradiction}, RealPoset [. 0,1 .]) by YELLOW_2:24;
       then 
       R. [x,y] "/\" R. [y,z] <<= (R (#) R). [x,z] by LFUZZY_0:22;
       then
       R. [x,y] "/\" R. [y,z] <= (R (#) R). [x,z] &
       (R (#) R). [x,z] <= R. [x,z] by LFUZZY_0:3,AS,Def2;
       then
       R. [x,y] "/\" R. [y,z] <= R. [x,z] by AXIOMS:22;       
       hence thesis by LFUZZY_0:3;      
      end;
     end;
     assume
A2:  for x,y,z being Element of X holds R. [x,y] "/\" R. [y,z] <<= R. [x,z];
     thus R (#) R c= R
      proof
       let x,z be Element of X;
       set W = rng min(R,R,x,z);
A3:    W <> {} &
       W = {R. [x,y'] "/\" R. [y',z] where y' is Element of X:
                      not contradiction} by Th2;
       for r being real number st r in W holds r <= R. [x,z]
        proof
         let r be real number;
         assume r in W;then
         r in {R. [x,y'] "/\" R. [y',z] where y' is Element of X:
                  not contradiction} by Th2;
         then
         consider y being Element of X such that
A4:      r = R. [x,y] "/\" R. [y,z];
         R. [x,y] "/\" R. [y,z] <<= R. [x,z] by A2;
         hence thesis by A4,LFUZZY_0:3;
        end;
       then
       upper_bound W <= R. [x,z] by A3,TOPMETR3:1;
       hence thesis by  FUZZY_4:def 4;        
      end;
    end;
  end;
end;

definition
  let X be non empty set;
  let R be RMembership_Func of X,X;
  attr R is antisymmetric means :Def9:
   for x,y being Element of X holds
     R. [x,y] <> 0 & R. [y,x] <> 0 implies x = y;
end;

definition
 let X be non empty set;
 let R be RMembership_Func of X,X;
 redefine attr R is antisymmetric means
 for x,y being Element of X holds
   R. [x,y] <> 0 & x <> y implies R. [y,x] = 0;
compatibility
  proof
    (for x,y being Element of X holds 
       R. [x,y] <> 0 & x <> y implies R. [y,x] = 0)
    implies
     for x,y being Element of X holds 
       R. [x,y] <> 0 & R. [y,x] <> 0 implies x = y;
    hence thesis by Def9;
  end;
end;

definition
 let X;
 cluster Imf(X,X) -> symmetric transitive reflexive antisymmetric;
 coherence
  proof
   thus Imf(X,X) is symmetric
    proof
        let x,y be Element of X;
        per cases;
        suppose
A1:     x=y;
        thus Imf(X,X). [x,y]
        = Imf(X,X). [y,x] by A1;
        suppose
A2:     not x=y;
        thus Imf(X,X). [x,y]
        = 0 by FUZZY_4:def 6,A2
        .= Imf(X,X). [y,x] by A2,FUZZY_4:def 6;        
    end;
   thus Imf(X,X) is transitive 
    proof
        let x,y,z be Element of X;
        per cases;
        suppose
A1:     x = z;
        thus thesis
        proof
         per cases;
         suppose
A11:     x = y;
         Imf(X,X). [x,y] "/\" Imf(X,X). [y,z]
          = min(Imf(X,X). [x,y], Imf(X,X). [y,z]) by LFUZZY_0:5
         .= 1 by FUZZY_4:def 6, A11, A1;then
         Imf(X,X). [x,y] "/\" Imf(X,X). [y,z]
         <= Imf(X,X). [x,z] by FUZZY_4:def 6,A1;
         hence thesis by LFUZZY_0:3;         
         suppose
A12:     not x=y;
           Imf(X,X). [x,y] "/\" Imf(X,X). [y,z]
            = min(Imf(X,X). [x,y],Imf(X,X). [y,z]) by LFUZZY_0:5
           .= min(Imf(X,X). [x,y],0) by FUZZY_4:def 6,A12,A1
           .= min(0,0) by FUZZY_4:def 6,A12
           .= 0;then
           Imf(X,X). [x,y] "/\" Imf(X,X). [y,z] <= 1;then
           Imf(X,X). [x,y] "/\" Imf(X,X). [y,z] <= Imf(X,X). [x,z]
         by FUZZY_4:def 6,A1;
           hence thesis by LFUZZY_0:3;
        end;
        suppose
A2:     not x=z;
        thus thesis
         proof
           per cases;
           suppose
A21:       x=y;
           Imf(X,X). [x,y] "/\" Imf(X,X). [y,z]
            = min(Imf(X,X). [x,y],Imf(X,X). [y,z]) by LFUZZY_0:5
           .= min(Imf(X,X). [x,y],0) by FUZZY_4:def 6,A21,A2
           .= min(1,0) by FUZZY_4:def 6,A21
           .= 0 by SQUARE_1:def 1;then
           Imf(X,X). [x,y] "/\" Imf(X,X). [y,z] <= Imf(X,X). [x,z]
         by FUZZY_4:def 6,A2;
           hence thesis by LFUZZY_0:3;
           suppose
A22:       x <> y;
           thus thesis
            proof
              per cases;
              suppose
A221:         y=z;
              Imf(X,X). [x,y] "/\" Imf(X,X). [y,z]
              = min(Imf(X,X). [x,y],Imf(X,X). [y,z]) by LFUZZY_0:5
              .= min(Imf(X,X). [x,y],1) by FUZZY_4:def 6,A221
              .= min(0,1) by FUZZY_4:def 6,A22
              .= 0 by SQUARE_1:def 1;then
              Imf(X,X). [x,y] "/\" Imf(X,X). [y,z] <= Imf(X,X). [x,z]
            by FUZZY_4:def 6,A2;
              hence thesis by LFUZZY_0:3;
              suppose
A222:         y <> z;
              Imf(X,X). [x,y] "/\" Imf(X,X). [y,z]
              = min(Imf(X,X). [x,y],Imf(X,X). [y,z]) by LFUZZY_0:5
              .= min(Imf(X,X). [x,y],0) by FUZZY_4:def 6,A222
              .= min(0,0) by FUZZY_4:def 6,A22
              .= 0;then
              Imf(X,X). [x,y] "/\" Imf(X,X). [y,z] <= Imf(X,X). [x,z]
            by FUZZY_4:def 6,A2;
              hence thesis by LFUZZY_0:3;
            end;         
         end;
    end;
   thus Imf(X,X) is reflexive
    proof
     thus for x being Element of X holds Imf(X,X). [x,x] = 1 by FUZZY_4:def 6;
    end;
   thus for x,y being Element of X holds 
    Imf(X,X). [x,y] <> 0 & x <> y implies Imf(X,X). [y,x] = 0 by FUZZY_4:def 6;
  end;
end;

definition
 let X;
 cluster reflexive transitive symmetric antisymmetric RMembership_Func of X,X;
 existence
  proof
   take Imf(X,X); thus thesis;
  end;
end;

theorem Th4:
for R,S being RMembership_Func of X,X holds 
R is symmetric & S is symmetric implies converse min(R,S) = min(R,S)
 proof
  let R,S be RMembership_Func of X,X;
  assume R is symmetric & S is symmetric;then
A1:converse R = R & converse S =S by Def5;
thus thesis by A1,FUZZY_4:11;
 end;

theorem Th5:
for R,S being RMembership_Func of X,X holds 
R is symmetric & S is symmetric implies converse max(R,S) = max(R,S) 
 proof
  let R,S be RMembership_Func of X,X;
  assume R is symmetric & S is symmetric;then
A1:converse R = R & converse S =S by Def5;
  thus thesis by FUZZY_4:9,A1;
 end;

definition
  let X;
  let R,S be symmetric RMembership_Func of X,X;
  cluster min(R,S) -> symmetric;
  coherence
   proof
     converse min(R,S) = min(R,S) by Th4;
     hence thesis by Def5;
   end;
  cluster max(R,S) -> symmetric;
  coherence
   proof
     converse max(R,S) = max(R,S) by Th5;
     hence thesis by Def5;
   end;
end;

theorem Th6:
for R,S being RMembership_Func of X,X holds
R is transitive & S is transitive implies min(R,S) (#) min(R,S) c= min(R,S)
  proof
   let R,S be RMembership_Func of X,X;
   assume R is transitive & S is transitive; then
Z1:   R(#)R c= R & S(#)S c= S by Def7;
     let x be Element of X, y be Element of X;
A2:  (min(R,S) (#) min(R,S)). [x,y]
       <= min(min(R,S) (#) R, min(R,S) (#) S). [x,y] by FUZZY_4:23;
     min(min(R,S) (#) R, min(R,S) (#) S). [x,y] 
     = min((min(R,S) (#) R). [x,y], (min(R,S) (#) S). [x,y]) &     
     (min(R,S) (#) R). [x,y] <= min(R(#)R, S(#)R). [x,y] &
     (min(R,S) (#) S). [x,y] <= min(R(#)S, S(#)S). [x,y] 
           by FUZZY_1:def 5,FUZZY_4:25;
     then
     min(min(R,S) (#) R, min(R,S) (#) S). [x,y] 
     <= min(min(R(#)R, S(#)R). [x,y],min(R(#)S, S(#)S). [x,y]) by Th7;
     then
A4:     (min(R,S) (#) min(R,S)). [x,y] 
     <= min(min(R(#)R, S(#)R). [x,y],min(R(#)S, S(#)S). [x,y]) 
      by A2,AXIOMS:22;
     min(R(#)R, S(#)R). [x,y] = min((R(#)R). [x,y], (S(#)R). [x,y]) &
     min(R(#)S, S(#)S). [x,y] = min((S(#)S). [x,y], (R(#)S). [x,y]) 
     by FUZZY_1:def 5;
     then
      min(R(#)R, S(#)R). [x,y] <= (R(#)R). [x,y] & 
     min(R(#)S, S(#)S). [x,y] <= (S(#)S). [x,y] &
     (R(#)R). [x,y] <= R. [x,y] & (S(#)S). [x,y] <= S. [x,y]
   by Z1,Def2,SQUARE_1:35;
     then
     min(R(#)R, S(#)R). [x,y] <= R. [x,y] & 
     min(R(#)S, S(#)S). [x,y] <= S. [x,y] by AXIOMS:22;
     then
     min(min(R(#)R, S(#)R). [x,y],min(R(#)S, S(#)S). [x,y]) 
     <= min(R. [x,y], S. [x,y]) by Th7;
     then
     (min(R,S) (#) min(R,S)). [x,y] <= min(R. [x,y], S. [x,y]) 
     by A4,AXIOMS:22;
     hence thesis by FUZZY_1:def 5;     
  end;

definition
 let X;
 let R,S be transitive RMembership_Func of X,X;
 cluster min(R,S) -> transitive;
 coherence
  proof
    min(R,S) (#) min(R,S) c= min(R,S) by Th6;
    hence thesis by Def7;
  end;
end;

definition let A be set, X be non empty set;
redefine func chi(A,X) -> Membership_Func of X;
coherence 
   proof
    dom chi(A,X) = X & rng chi(A,X) c= [. 0,1 .] by FUZZY_1:1,FUNCT_3:def 3;   
    hence chi(A,X) is Membership_Func of X by FUZZY_1:def 1;
   end;
end;

theorem
for r being Relation of X st r is_reflexive_in X
holds chi(r,[:X,X:]) is reflexive
  proof
   let r be Relation of X;
   assume
A1:r is_reflexive_in X;
   for x being Element of X holds chi(r,[:X,X:]). [x,x] = 1
    proof
     let x be Element of X;
     [x,x] in r by RELAT_2:def 1,A1;
     hence thesis by FUNCT_3:def 3;     
    end;
   hence thesis by Def4;
  end;
  
theorem
for r being Relation of X st r is antisymmetric
holds chi(r,[:X,X:]) is antisymmetric
  proof
   let r be Relation of X;
   assume r is antisymmetric;then
A1:r is_antisymmetric_in field r by RELAT_2:def 12;   
   for x,y being Element of X holds  
   chi(r,[:X,X:]). [x,y] <> 0 & chi(r,[:X,X:]). [y,x] <> 0 implies x = y
    proof
     let x,y be Element of X;
     assume chi(r,[:X,X:]). [x,y] <> 0 & chi(r,[:X,X:]). [y,x] <> 0;then
A2:  [x,y] in r & [y,x] in r by FUNCT_3:def 3;
     x in field r & y in field r & [x,y] in r & [y,x] in r
       implies x = y by RELAT_2:def 4,A1;
     hence thesis by A2,RELAT_1:30;
    end;
   hence thesis by Def9;
  end;

theorem
for r being Relation of X st r is symmetric
holds chi(r,[:X,X:]) is symmetric
  proof
   let r be Relation of X;
   assume r is symmetric;then
A1:r is_symmetric_in field r by RELAT_2:def 11;
     let x,y be Element of X;
A2:  (x in field r & y in field r & [x,y] in r implies [y,x] in r) &
     (x in field r & y in field r & [y,x] in r implies [x,y] in r)
               by RELAT_2:def 3,A1;
     per cases;
     suppose 
A3:  [x,y] in r;
     chi(r,[:X,X:]). [x,y] = 1 & chi(r,[:X,X:]). [y,x] = 1 by A2,
     RELAT_1:30,A3,FUNCT_3:def 3;
     hence thesis;
     suppose
A4:  not [x,y] in r;
     not [y,x] in r by A2,RELAT_1:30,A4; then
     chi(r,[:X,X:]). [x,y] = 0 & chi(r,[:X,X:]). [y,x] = 0 by A4,FUNCT_3:def 3;
     hence thesis;
  end;

theorem
for r being Relation of X st r is transitive
holds chi(r,[:X,X:]) is transitive
  proof
   let r be Relation of X;
   assume r is transitive;then
A1:r is_transitive_in field r by RELAT_2:def 16;
     let x,y,z be Element of X;
A2:  x in field r & y in field r & z in field r & [x,y] in r & [y,z] in r
       implies [x,z] in r by RELAT_2:def 8,A1;
      per cases;
       suppose 
B1:    [x,y] in r;
       thus thesis
        proof
        per cases;
         suppose 
B2:      [y,z] in r;
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
         = min(chi(r,[:X,X:]). [x,y] , chi(r,[:X,X:]). [y,z]) by LFUZZY_0:5 
         .= min(1,chi(r,[:X,X:]). [y,z]) by B1,FUNCT_3:def 3
         .= min(1,1) by B2,FUNCT_3:def 3
         .= chi(r,[:X,X:]). [x,z] by RELAT_1:30,B1,B2,A2,FUNCT_3:def 3;
         hence thesis by LFUZZY_0:3;
         suppose 
B3:      not [y,z] in r;
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
         = min(chi(r,[:X,X:]). [x,y] , chi(r,[:X,X:]). [y,z]) by LFUZZY_0:5 
         .= min(1,chi(r,[:X,X:]). [y,z]) by B1,FUNCT_3:def 3
         .= min(1,0) by B3,FUNCT_3:def 3
         .= 0 by SQUARE_1:def 1;
         then
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
            <= chi(r,[:X,X:]). [x,z] by FUZZY_2:1;
         hence thesis by LFUZZY_0:3;
        end;
       suppose 
B4:    not [x,y] in r;
       thus thesis
        proof
        per cases;
         suppose 
B5:      [y,z] in r;
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
         = min(chi(r,[:X,X:]). [x,y] , chi(r,[:X,X:]). [y,z]) by LFUZZY_0:5 
         .= min(0,chi(r,[:X,X:]). [y,z]) by B4,FUNCT_3:def 3
         .= min(0,1) by B5,FUNCT_3:def 3
         .= 0 by SQUARE_1:def 1;
         then
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
            <= chi(r,[:X,X:]). [x,z] by FUZZY_2:1;
         hence thesis by LFUZZY_0:3;
         suppose 
B6:      not [y,z] in r;
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
         = min(chi(r,[:X,X:]). [x,y] , chi(r,[:X,X:]). [y,z]) by LFUZZY_0:5 
         .= min(0,chi(r,[:X,X:]). [y,z]) by B4,FUNCT_3:def 3
         .= min(0,0) by B6,FUNCT_3:def 3
         .= 0;
         then
         chi(r,[:X,X:]). [x,y] "/\" chi(r,[:X,X:]). [y,z] 
            <= chi(r,[:X,X:]). [x,z] by FUZZY_2:1;
         hence thesis by LFUZZY_0:3;
        end;     
  end;

theorem
  Zmf(X,X) is symmetric antisymmetric transitive
  proof
   thus Zmf(X,X) is symmetric
    proof
       let x,y be Element of X;
       Zmf(X,X). [x,y] = 0 & Zmf(X,X). [y,x] = 0 by FUZZY_4:32;
       hence thesis;
    end;
   thus Zmf(X,X) is antisymmetric
    proof
       let x,y be Element of X;
       thus thesis by FUZZY_4:32;
    end;
   thus Zmf(X,X) is transitive 
    proof
       let x,y,z be Element of X;
A1:    Zmf(X,X). [x,y] "/\" Zmf(X,X). [y,z] 
       = min(Zmf(X,X). [x,y], Zmf(X,X). [y,z]) by LFUZZY_0:5
       .= min(0, Zmf(X,X). [y,z]) by FUZZY_4:32 
       .= min(0,0) by FUZZY_4:32
       .= 0;
       Zmf(X,X). [x,z] = 0 by FUZZY_4:32;
       hence thesis by LFUZZY_0:3,A1;
    end;
  end;

theorem
Umf(X,X) is symmetric transitive reflexive
  proof
   thus Umf(X,X) is symmetric
    proof
        let x,y be Element of X;
        thus Umf(X,X). [x,y]
        = 1 by FUZZY_4:31
        .= Umf(X,X). [y,x] by FUZZY_4:31;
    end;
   thus Umf(X,X) is transitive 
    proof
        let x,y,z be Element of X;
        Umf(X,X). [x,y] "/\" Umf(X,X). [y,z]
        = min(Umf(X,X). [x,y], Umf(X,X). [y,z]) by LFUZZY_0:5
        .= min(1,Umf(X,X). [y,z]) by FUZZY_4:31
        .= min(1,1) by FUZZY_4:31
        .= 1;then
        Umf(X,X). [x,y] "/\" Umf(X,X). [y,z]
        <= Umf(X,X). [x,z] by FUZZY_4:31;
        hence thesis by LFUZZY_0:3;
    end;
   thus Umf(X,X) is reflexive
    proof
     let x be Element of X;
     thus thesis by FUZZY_4:31;
    end;
  end;

theorem
for R being RMembership_Func of X,X holds max(R,converse R) is symmetric
  proof
   let R be RMembership_Func of X,X;
   set S = max(R,converse R);
   let x,y be Element of X;
   thus S. [x,y] = max(R. [x,y], (converse R). [x,y]) by FUZZY_1:def 6
       .= max(R. [x,y], R. [y,x]) by FUZZY_4:def 1
       .= max((converse R). [y,x], R. [y,x]) by FUZZY_4:def 1
       .= S. [y,x] by FUZZY_1:def 6;
  end;

theorem
for R being RMembership_Func of X,X holds min(R,converse R) is symmetric
  proof
   let R be RMembership_Func of X,X;
   set S = min(R,converse R);
   let x,y be Element of X;
   thus 
     S. [x,y] = min(R. [x,y], (converse R). [x,y]) by FUZZY_1:def 5
       .= min(R. [x,y], R. [y,x]) by FUZZY_4:def 1
       .= min((converse R). [y,x], R. [y,x]) by FUZZY_4:def 1
       .= S. [y,x] by FUZZY_1:def 5;
  end;

theorem
for R being RMembership_Func of X,X 
for R' being RMembership_Func of X,X
 st R' is symmetric & R c= R'
 holds max(R, converse R) c= R'
  proof
   let R be RMembership_Func of X,X;
   let T be RMembership_Func of X,X;
   assume 
AB0:     T is symmetric & R c= T;
       let x,y be Element of X;
A6:    R. [x,y] <= T. [x,y] & R. [y,x] <= T. [y,x] by AB0,Def1;
       then
       R. [y,x] <= T. [x,y] by AB0,Def6;
       then       
       max(R. [x,y], R. [y,x]) <= T. [x,y] by A6,SQUARE_1:50; then
       max(R. [x,y], (converse R). [x,y]) <= T. [x,y] by FUZZY_4:def 1;
       hence thesis by FUZZY_1:def 6;        
  end;

theorem
for R being RMembership_Func of X,X 
for R' being RMembership_Func of X,X
 st R' is symmetric & R' c= R
 holds R' c= min(R, converse R)
  proof
   let R be RMembership_Func of X,X;
   let T be RMembership_Func of X,X;
   assume 
AB0:     T is symmetric & T c= R;
       let x,y be Element of X;
A6:    T. [x,y] <= R. [x,y] & T. [y,x] <= R. [y,x] by AB0,Def1;
       then
       T. [x,y] <= R. [y,x] by AB0,Def6;
       then       
       T. [x,y] <= min(R. [x,y], R. [y,x]) by A6,SQUARE_1:39; then
       T. [x,y] <= min(R. [x,y], (converse R). [x,y]) by FUZZY_4:def 1;
       hence thesis by FUZZY_1:def 5;
  end;

begin :: Transitive closure of a fuzzy relation

definition
  let X be non empty set;
  let R be RMembership_Func of X,X;
  let n be natural number;
   func n iter R -> RMembership_Func of X,X means :Def11:
   ex F being Function of NAT,Funcs([:X,X:],[. 0,1 .]) st
   it = F.n & F.0 = Imf(X,X) &
   for k being natural number ex Q being RMembership_Func of X,X st
   F.k = Q & F.(k + 1) = Q (#) R;
    existence
     proof
       set D = the carrier of FuzzyLattice [:X,X:];
       defpred P[set,set,set] means
       ex Q being Element of D st $2 = Q & $3 = @Q (#) R;       
A1:    for k being Element of NAT for x being Element of D
       ex y being Element of D st P[k,x,y]
        proof
          let k be Element of NAT;
          let Q be Element of D;          
          set y = @Q (#) R;
          reconsider y' = ([:X,X:],y)@ as Element of D;
          take y';
          y' = @Q (#) R by LFUZZY_0:def 6;
          hence P[k,Q,y'];
        end;
       consider F being Function of NAT,D such that
A2:    F.0 = ([:X,X:],Imf(X,X))@ &
       for k being Element of NAT holds P[k,F.k,F.(k+1)] from RecExD(A1);
       Funcs([:X,X:],[. 0,1 .]) = the carrier of FuzzyLattice [:X,X:]
         by LFUZZY_0:14;then
       reconsider F as Function of NAT,Funcs([:X,X:],[. 0,1 .]);
       reconsider n' = n as Element of NAT by ORDINAL2:def 21;
       reconsider IT = F.n' as Element of FuzzyLattice [:X,X:]
         by LFUZZY_0:14;
       reconsider IT' = @(IT) as RMembership_Func of X,X;
       take IT';
       thus ex F being Function of NAT,Funcs([:X,X:],[. 0,1 .]) st
       IT' = F.n & F.0 = Imf(X,X) &
       for k being natural number ex Q being RMembership_Func of X,X st
       F.k = Q & F.(k + 1) = Q (#) R
        proof
          take F;
          thus IT' = F.n by LFUZZY_0:def 5;
          thus F.0 = Imf(X,X) by A2,LFUZZY_0:def 6;
          thus for k being natural number ex Q being RMembership_Func of X,X st
          F.k = Q & F.(k + 1) = Q (#) R
           proof
             let k be natural number;
             reconsider n=k as Element of NAT by ORDINAL2:def 21;
             reconsider Q' = F.n as Element of D by LFUZZY_0:14;
             reconsider Q = @Q' as RMembership_Func of X,X;
             take Q;
             thus F.k = Q by LFUZZY_0:def 5;
             P[n,F.n,F.(n+1)] by A2;
             hence F.(k + 1) = Q (#) R;
           end;
        end;   
     end;
    uniqueness
     proof
       let S,T be RMembership_Func of X,X;
       given F being Function of NAT,Funcs([:X,X:],[. 0,1 .]) such that
A3:    S = F.n & F.0 = Imf(X,X) &
       for k being natural number ex Q being RMembership_Func of X,X st
       F.k = Q & F.(k + 1) = Q (#) R;
       given G being Function of NAT,Funcs([:X,X:],[. 0,1 .]) such that
A4:    T = G.n & G.0 = Imf(X,X) &
       for k being natural number ex Q being RMembership_Func of X,X st
       G.k = Q & G.(k + 1) = Q (#) R;
       defpred P[natural number] means F.$1 = G.$1;
A1:    P[0] by A3,A4;
A2:    for k being natural number st P[k] holds P[k+1]
        proof
           let k be natural number;
           assume
A5:        F.k = G.k;
           consider Q being RMembership_Func of X,X such that
A6:        G.k = Q & G.(k + 1) = Q (#) R by A4;
           consider Q' being RMembership_Func of X,X such that
A7:        F.k = Q' & F.(k + 1) = Q' (#) R by A3;
           thus F.(k + 1) = G.(k+1) by A6,A7,A5;
        end;       
       for k being natural number holds P[k] from Nat_Ind(A1,A2);
       hence S=T by A3,A4;
     end;    
end;

reserve X for non empty set;
reserve R for RMembership_Func of X,X;

theorem th15:
  Imf(X,X) (#) R = R
    proof
A1:   dom (Imf(X,X) (#) R) = [:X,X:] by FUZZY_1:def 1
      .= dom R by FUZZY_1:def 1;
      for x,y being set st [x,y] in dom (Imf(X,X) (#) R)
      holds (Imf(X,X) (#) R). [x,y] = R. [x,y]
        proof
          let x,y be set;
          assume [x,y] in dom (Imf(X,X) (#) R);then
          reconsider x,y as Element of X by ZFMISC_1:106;
A2:       (Imf(X,X) (#) R). [x,y] =
          "\/"({Imf(X,X). [x,z] "/\" R. [z,y]
           where z is Element of X: not contradiction}, RealPoset [. 0,1 .])
            by LFUZZY_0:22;
          set S = {Imf(X,X). [x,z] "/\" R. [z,y]
           where z is Element of X: not contradiction};           
A3:       R. [x,y] is_>=_than S
            proof
              for c being Element of RealPoset [. 0,1 .] st c in S holds
              c <<= R. [x,y]
                proof
                  let c be Element of RealPoset [. 0,1 .];
                  assume c in S;then
                  consider z being Element of X such that
A4:               c = Imf(X,X). [x,z] "/\" R. [z,y];
                  per cases;
                  suppose
A5:                  x = z;
A6:               R. [z,y] <= 1 by FUZZY_4:4;
                  c = min(Imf(X,X). [x,z],R. [z,y]) by LFUZZY_0:5,A4           
                  .= min(R. [z,y],1) by   A5,FUZZY_4:def 6
                  .= R. [x,y] by A5,SQUARE_1:def 1,A6;
                  hence thesis by LFUZZY_0:3;
                  suppose
A7:                  x <> z;
A8:               0 <= R. [z,y] by FUZZY_4:4;
                  c = min(Imf(X,X). [x,z],R. [z,y]) by LFUZZY_0:5,A4
                  .= min(R. [z,y],0) by A7,FUZZY_4:def 6
                  .= 0 by SQUARE_1:def 1,A8;
                  then
                  c <= R. [x,y] by FUZZY_4:4;
                  hence thesis by LFUZZY_0:3;
                end;
              hence thesis by LATTICE3:def 9;
            end;
          for b being Element of RealPoset [. 0,1 .]
                        st b is_>=_than S holds R. [x,y] <<= b
            proof
              let b be Element of RealPoset [. 0,1 .];
              assume AB:b is_>=_than S;
A10:          R. [x,y] <= 1 by FUZZY_4:4;
              Imf(X,X). [x,x] "/\" R. [x,y]
               = min(Imf(X,X). [x,x], R. [x,y]) by LFUZZY_0:5
              .= min(1, R. [x,y]) by FUZZY_4:def 6                  
              .= R. [x,y] by SQUARE_1:def 1,A10;
              then
              R. [x,y] in S;
              hence thesis by AB,LATTICE3:def 9;
            end;
          hence thesis by A3,YELLOW_0:32,A2;
        end;
      hence thesis by PARTFUN1:35,A1;
    end;
    
theorem th16:
  R (#) Imf(X,X) = R
    proof
A1:   dom (R (#) Imf(X,X)) = [:X,X:] by FUZZY_1:def 1
      .= dom R by FUZZY_1:def 1;
      for x,y being set st [x,y] in dom (R (#) Imf(X,X))
      holds (R (#) Imf(X,X)). [x,y] = R. [x,y]  
        proof
          let x,y be set;
          assume [x,y] in dom (R (#) Imf(X,X));then
          reconsider x,y as Element of X by ZFMISC_1:106;
A2:       (R (#) Imf(X,X)). [x,y] =
          "\/"({R. [x,z] "/\" Imf(X,X). [z,y]
           where z is Element of X: not contradiction}, RealPoset [. 0,1 .])
            by LFUZZY_0:22;
          set S = {R. [x,z] "/\" Imf(X,X). [z,y]
           where z is Element of X: not contradiction};           
A3:       R. [x,y] is_>=_than S
            proof
              for c being Element of RealPoset [. 0,1 .] st c in S holds
              c <<= R. [x,y]
                proof
                  let c be Element of RealPoset [. 0,1 .];
                  assume c in S;then
                  consider z being Element of X such that
A4:               c = R. [x,z] "/\" Imf(X,X). [z,y];
                  per cases;
                  suppose
A5:                  y = z;
A6:               R. [x,z] <= 1 by FUZZY_4:4;
                  c = min(R. [x,z],Imf(X,X). [z,y]) by LFUZZY_0:5 ,A4          
                  .= min(R. [x,z],1) by A5,FUZZY_4:def 6                  
                  .= R. [x,y] by SQUARE_1:def 1,A6,A5;
                  hence thesis by LFUZZY_0:3;
                  suppose
A7:               not y = z;
A8:               0 <= R. [x,z] by FUZZY_4:4;
                  c = min(R. [x,z],Imf(X,X). [z,y]) by LFUZZY_0:5,A4
                  .= min(R. [x,z],0) by A7,FUZZY_4:def 6
                  .= 0 by SQUARE_1:def 1,A8;
                  then
                  c <= R. [x,y] by FUZZY_4:4;
                  hence thesis by LFUZZY_0:3;
                end;
              hence thesis by LATTICE3:def 9;
            end;
          for b being Element of RealPoset [. 0,1 .]
                        st b is_>=_than S holds R. [x,y] <<= b
            proof
              let b be Element of RealPoset [. 0,1 .];
              assume AA:b is_>=_than S;
A10:          R. [x,y] <= 1 by FUZZY_4:4;
              R. [x,y] "/\" Imf(X,X). [y,y]  
               = min(R. [x,y],Imf(X,X). [y,y]) by LFUZZY_0:5
              .= min( R. [x,y],1) by FUZZY_4:def 6                  
              .= R. [x,y] by SQUARE_1:def 1,A10;
              then
              R. [x,y] in S;
              hence thesis by AA,LATTICE3:def 9;           
            end;
          hence thesis by A3,YELLOW_0:32,A2;
        end;
      hence thesis by PARTFUN1:35,A1;
    end;

theorem th18:
  0 iter R = Imf(X,X)
  proof
   consider F being Function of NAT,Funcs([:X,X:],[. 0,1 .]) such that
A1:0 iter R = F.0 & F.0 = Imf(X,X) &
   for k being natural number ex Q being RMembership_Func of X,X st
   F.k = Q & F.(k + 1) = Q (#) R by Def11;
   thus thesis by A1;
  end;

theorem th20:
  1 iter R = R
  proof
   consider F being Function of NAT,Funcs([:X,X:],[. 0,1 .]) such that
A1:1 iter R = F.1 & F.0 = Imf(X,X) &
   for k being natural number ex Q being RMembership_Func of X,X st
   F.k = Q & F.(k + 1) = Q (#) R by Def11;
   consider Q being RMembership_Func of X,X such that
A2:F.0 = Q & F.(0 + 1) = Q (#) R by A1;
   thus 1 iter R  = R by A1,A2,th15;
  end;

theorem th17:
  for n being natural number holds (n+1) iter R = (n iter R) (#) R
    proof
      let n be natural number;
      consider f being Function of NAT,Funcs([:X,X:],[. 0,1 .]) such that
A1:   (n+1) iter R = f.(n+1) & f.0 = Imf(X,X) and
A2:   for k being natural number ex Q being RMembership_Func of X,X st
      f.k = Q & f.(k + 1) = Q (#) R by Def11;      
      ex Q being RMembership_Func of X,X st f.n = Q & f.(n + 1) = Q(#)R by A2;
      hence thesis by A1,A2,Def11;
    end;

theorem th19:
  for m,n being natural number holds (m+n) iter R = (m iter R) (#) (n iter R)
    proof
      let m,n be natural number;
      defpred P[natural number] means
      (m+ $1) iter R = (m iter R) (#) ($1 iter R);
      (m iter R) (#) (0 iter R) = (m iter R) (#) Imf(X,X) by th18
      .= m iter R by th16;then
A2:   P[0];
A3:   for n being natural number st P[n] holds P[n+1]
        proof
          let n be natural number;
          assume
A1:       (m+n) iter R = (m iter R) (#) (n iter R);
          thus ((m) iter R) (#) ((n+1) iter R)
          = (m iter R) (#) ((n iter R) (#)R ) by th17
          .= ((m+n) iter R) (#) R by A1,LFUZZY_0:23
          .= ((m+n)+1) iter R by th17
          .= (m+(n+1)) iter R by XCMPLX_1:1;
        end;
        for m being natural number holds P[m] from Nat_Ind(A2,A3);
        hence thesis;      
    end;

theorem
  for m,n being natural number holds (m*n) iter R = m iter (n iter R)
    proof
      let m,n be natural number;
      defpred P[natural number] means
      ($1 * n) iter R = $1 iter (n iter R);
      (0*n) iter R
      = Imf(X,X) by th18
      .= 0 iter (n iter R) by th18;
      then
A1:   P[0];
A2:   for m being natural number st P[m] holds P[m+1]
        proof
          let m be natural number;
          assume
A3:       (m*n) iter R = m iter (n iter R);
A4:          ((m+1)*n) iter R
          = (m*n + 1*n) iter R by XCMPLX_1:8
          .= (m iter (n iter R)) (#) (n iter R) by A3,th19;
          (m+1) iter (n iter R)
           = (m iter (n iter R)) (#) (1 iter (n iter R)) by th19
          .= (m iter (n iter R)) (#) (n iter R) by th20;
          hence thesis by A4;
        end;
      for m being natural number holds P[m] from Nat_Ind(A1,A2);
      hence thesis;
    end;  

definition
  let X be non empty set;
  let R be RMembership_Func of X,X;
  func TrCl R -> RMembership_Func of X,X equals :Def12:
  "\/"({n iter R where n is Nat : n > 0},FuzzyLattice [:X,X:]);
  coherence  
    proof
      set S = "\/"({n iter R where n is Nat : n > 0},FuzzyLattice [:X,X:]);
      S = @S by LFUZZY_0:def 5;
      hence S is RMembership_Func of X,X;      
    end;
end;

theorem lemma:
  for x,y being Element of X holds
    (TrCl R). [x,y]
    = "\/"(pi({n iter R where n is Nat : n > 0}, [x,y]), RealPoset [. 0,1 .])
        proof
          let x,z be Element of X;
          set Q = {n iter R where n is Nat : n > 0};
A1:   FuzzyLattice [:X,X:] = (RealPoset [. 0,1 .]) |^ [:X,X:] by LFUZZY_0:def 4
       .= product ([:X,X:] --> RealPoset [. 0,1 .]) by YELLOW_1:def 5;
      Q c= the carrier of FuzzyLattice [:X,X:]
        proof
          let t be set;
          assume t in Q;then
          consider n being Nat  such that
A4:       t = n iter R & n > 0;
          reconsider t as Membership_Func of [:X,X:] by A4;
          ([:X,X:],t)@ is Element of FuzzyLattice [:X,X:];
          then
          reconsider t as Element of FuzzyLattice [:X,X:] by LFUZZY_0:def 6;
          t in the carrier of FuzzyLattice [:X,X:];
          hence thesis;
        end;then
      reconsider Q as Subset of FuzzyLattice [:X,X:];
          reconsider i = [x,z] as Element of [:X,X:];
A2:       for a being Element of [:X,X:] holds
          ([:X,X:] --> RealPoset [. 0,1 .]).a is complete LATTICE
          by FUNCOP_1:13;
          (sup Q).i = "\/"(pi(Q,i), ([:X,X:] --> RealPoset [. 0,1 .]).i)
          by A1,A2,WAYBEL_3:32;
          then
          ("\/"(Q,FuzzyLattice [:X,X:])). [x,z]
          = "\/"(pi(Q, [x,z]), RealPoset [. 0,1 .]) by FUNCOP_1:13;
          hence thesis by Def12;
        end;

theorem th35:
  R c= TrCl R
    proof
     for c being Element of [: X,X :] holds R.c <= (TrCl R).c
       proof
       let c be Element of [: X,X :];
       set Q = {n iter R where n is Nat : n > 0};
       consider x,y being set such that 
A3:    [x,y] = c by ZFMISC_1:102;
       reconsider x,y as Element of X by ZFMISC_1:106,A3;
A4:    (TrCl R). [x,y]   = "\/"(pi(Q, [x,y]), RealPoset [. 0,1 .]) by lemma;
       R = 1 iter R by th20;then
       R in Q;then
       R. [x,y] in pi(Q, [x,y]) by CARD_3:def 6;
       then
       R. [x,y] <<= (TrCl R). [x,y] by A4,YELLOW_2:24;
       hence thesis by LFUZZY_0:3,A3;        
      end;
     hence thesis by Def1;
    end;

theorem th33:
  for n being natural number st n > 0 holds n iter R c= TrCl R
    proof
      let n' be natural number;
      assume
A1:      n' > 0;
      for c being Element of [: X,X :] holds (n' iter R).c <= (TrCl R).c
        proof
       let c be Element of [: X,X :];
       set Q = {n iter R where n is Nat : n > 0};
       consider x,y being set such that 
A3:    [x,y] = c by ZFMISC_1:102;
       reconsider x,y as Element of X by ZFMISC_1:106,A3;
A4:    (TrCl R). [x,y]   = "\/"(pi(Q, [x,y]), RealPoset [. 0,1 .]) by lemma;
       reconsider n' as Nat by ORDINAL2:def 21;
       n' iter R in Q by A1;then
       (n' iter R). [x,y] in pi(Q, [x,y]) by CARD_3:def 6;
       then
       (n' iter R). [x,y] <<= (TrCl R). [x,y] by A4,YELLOW_2:24;
       hence thesis by LFUZZY_0:3,A3;        
      end;
     hence thesis by Def1;
    end;

theorem th22:
  for Q being Subset of FuzzyLattice X,
  x being Element of X holds
  ("\/"(Q,FuzzyLattice X)). x = "\/"(pi(Q, x), RealPoset [. 0,1 .])
    proof
      let Q be Subset of FuzzyLattice X;
      let x be Element of X;
A1:   FuzzyLattice X = (RealPoset [. 0,1 .]) |^ X by LFUZZY_0:def 4
       .= product (X --> RealPoset [. 0,1 .]) by YELLOW_1:def 5;
A2:       for a being Element of X holds
          (X --> RealPoset [. 0,1 .]).a is complete LATTICE
          by FUNCOP_1:13;
          (sup Q).x = "\/"(pi(Q,x), (X --> RealPoset [. 0,1 .]).x)
          by A1,A2,WAYBEL_3:32;
          hence
          ("\/"(Q,FuzzyLattice X)). x
          = "\/"(pi(Q, x), RealPoset [. 0,1 .]) by FUNCOP_1:13;
    end;

th23:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
  {R. [x,y] "/\" (@("\/"(Q,FuzzyLattice [:X,X:]))). [y,z]
            where y is Element of X: not contradiction}
     = {R. [x,y] "/\" "\/"(pi(Q, [y,z]), RealPoset [. 0,1 .])
            where y is Element of X:not contradiction}
    proof
      let R be RMembership_Func of X,X;
      let Q be Subset of FuzzyLattice [:X,X:];
      let x,z be Element of X;
      defpred P[Element of X] means not contradiction;
      deffunc F(Element of X) =
      R. [x,$1] "/\" (@("\/"(Q,FuzzyLattice [:X,X:]))). [$1,z];
      deffunc G(Element of X) =
      R. [x,$1] "/\" "\/"(pi(Q, [$1,z]), RealPoset [. 0,1 .]);
      for y being Element of X holds
      R. [x,y] "/\" (@("\/"(Q,FuzzyLattice [:X,X:]))). [y,z]
      = R. [x,y] "/\" "\/"(pi(Q, [y,z]), RealPoset [. 0,1 .])
        proof
          let y be Element of X;
          (@("\/"(Q,FuzzyLattice [:X,X:]))). [y,z]
          = (("\/"(Q,FuzzyLattice [:X,X:]))). [y,z] by LFUZZY_0:def 5
          .= "\/"(pi(Q, [y,z]), RealPoset [. 0,1 .]) by th22;
          hence thesis;
        end;
      then
A1:   for y being Element of X holds F(y) = G(y);
      thus {F(y) where y is Element of X: P[y]}
      = {G(y') where y' is Element of X: P[y']} from FraenkelF'(A1);
    end;
    
theorem LFUZZY015:
  for R being complete Heyting LATTICE,
  X being Subset of R,
  y be Element of R holds
  y "/\" "\/"(X,R) = "\/"({y "/\" x where x is Element of R: x in X},R)
proof
 let R be complete Heyting LATTICE,
 X be Subset of R,
 y be Element of R;
 for z being Element of R holds z "/\" has_an_upper_adjoint
  by WAYBEL_1:def 19;
    hence thesis by WAYBEL_1:67;
end;

th24:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
  {R. [x,y] "/\" "\/"(pi(Q, [y,z]), RealPoset [. 0,1 .])
         where y is Element of X:not contradiction}
  =  {"\/"({R. [x,y'] "/\" b  where b is Element of RealPoset [. 0,1 .]:
       b in pi(Q,[y',z])} ,RealPoset [. 0,1 .])
         where y' is Element of X:not contradiction}
    proof
      let R be RMembership_Func of X,X;
      let Q be Subset of FuzzyLattice [:X,X:];
      let x,z be Element of X;
      defpred P[Element of X] means not contradiction;
      deffunc F(Element of X) =
      R. [x,$1] "/\" "\/"(pi(Q, [$1,z]), RealPoset [. 0,1 .]);
      deffunc G(Element of X) =
      "\/"({R. [x,$1] "/\" b  where b is Element of RealPoset [. 0,1 .]:
       b in pi(Q,[$1,z])} ,RealPoset [. 0,1 .]);
      for y being Element of X holds
      R. [x,y] "/\" "\/"(pi(Q, [y,z]), RealPoset [. 0,1 .])
      =  "\/"({R. [x,y] "/\" b  where b is Element of RealPoset [. 0,1 .]:
       b in pi(Q,[y,z])} ,RealPoset [. 0,1 .])
        proof
          let y be Element of X;
A1:       FuzzyLattice [:X,X:]
          = (RealPoset [. 0,1 .]) |^ [:X,X:] by LFUZZY_0:def 4
          .= product ([:X,X:] --> RealPoset [. 0,1 .]) by YELLOW_1:def 5;
          reconsider Q as Subset of
          product ([:X,X:] --> RealPoset [. 0,1 .]) by A1;
          pi(Q, [y,z]) is Subset of RealPoset [. 0,1 .] by FUNCOP_1:13;
          hence thesis by LFUZZY015;
        end;
      then
A1:   for y being Element of X holds F(y) = G (y);
      {F(y) where y is Element of X:P[y]}
      = {G(y) where y is Element of X:P[y]} from FraenkelF'(A1);
      hence thesis;
    end;

th25:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
  {"\/"({R. [x,y] "/\" b where b is Element of RealPoset [. 0,1 .]:
    b in pi(Q,[y,z])} ,RealPoset [. 0,1 .])
         where y is Element of X:not contradiction}
  = {"\/"({R. [x,y'] "/\" r. [y',z]
      where r is Element of FuzzyLattice [:X,X:]: r in Q} ,RealPoset [. 0,1 .])
         where y' is Element of X:not contradiction}
    proof
      let R be RMembership_Func of X,X;
      let Q be Subset of FuzzyLattice [:X,X:];
      let x,z be Element of X;
      set RP = RealPoset [. 0,1 .], FL = FuzzyLattice [:X,X:];
      defpred P[Element of X] means not contradiction;
      deffunc F(Element of X) =
      "\/"({R. [x,$1] "/\" b where b is Element of RP: b in pi(Q,[$1,z])} ,RP);
      deffunc G(Element of X) =
      "\/"({R. [x,$1] "/\" r. [$1,z] where r is Element of FL: r in Q} ,RP);
      for y being Element of X holds
      "\/"({R. [x,y] "/\" b where b is Element of RP: b in pi(Q,[y,z])} ,RP)
      = "\/"({R. [x,y] "/\" r. [y,z] where r is Element of FL: r in Q} ,RP)
        proof
          let y be Element of X;
          set A = {R. [x,y] "/\" b where b is Element of RP: b in pi(Q,[y,z])},
          B = {R. [x,y] "/\" r. [y,z] where r is Element of FL: r in Q};
          A = B
           proof
             thus A c= B
               proof
                 let a be set;
                 assume a in A;then
                 consider b be Element of RP such that
A2:              a = R. [x,y] "/\" b & b in pi(Q,[y,z]);
                 consider f be Function such that
A3:              f in Q & b = f. [y,z] by CARD_3:def 6,A2;
                 thus thesis by A2,A3;
               end;
             thus B c= A
             proof
               let a be set;
               assume a in B;then
               consider r being Element of FL such that
A4:               a = R. [x,y] "/\" r. [y,z] & r in Q;
               r. [y,z] in pi(Q,[y,z]) by CARD_3:def 6,A4;
               hence thesis by A4;
             end;
           end;
          hence thesis;
        end;then
A1:   for y being Element of X holds F(y) = G (y);
      thus {F(y) where y is Element of X:P[y]}
      = {G(y) where y is Element of X:P[y]} from FraenkelF'(A1);
    end;

th26:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
  {"\/"({R. [x,y] "/\" r. [y,z]
         where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
         where r is Element of FuzzyLattice [:X,X:]: r in Q}
   = {"\/"({R. [x,y] "/\" @(r'). [y,z]
         where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
         where r' is Element of FuzzyLattice [:X,X:]: r' in Q}
     proof
       let R be RMembership_Func of X,X;
       let Q be Subset of FuzzyLattice [:X,X:];
       let x,z be Element of X;
       set FL = FuzzyLattice [:X,X:];
       defpred P[Element of FL] means $1 in Q;
       deffunc F(Element of FL)
       = "\/"({R. [x,y] "/\" $1. [y,z]
         where y is Element of X:not contradiction} ,RealPoset [. 0,1 .]);
       deffunc G(Element of FL)
       = "\/"({R. [x,y] "/\" @($1). [y,z]
         where y is Element of X:not contradiction} ,RealPoset [. 0,1 .]);
       for r being Element of FL st r in Q holds
         "\/"({R. [x,y] "/\" r. [y,z]
           where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
         = "\/"({R. [x,y] "/\" @(r). [y,z]
           where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
         proof
           let r be Element of FL;
           assume r in Q;
           {R. [x,y] "/\" r. [y,z]  where y is Element of X:not contradiction}
           ={R. [x,y] "/\" @r. [y,z] where y is Element of X:not contradiction}
             proof
               defpred P[Element of X] means not contradiction;
               deffunc f(Element of X) = R. [x,$1] "/\" r. [$1,z];
               deffunc g(Element of X) = R. [x,$1] "/\" @r. [$1,z];
A2:            for y being Element of X holds f(y) = g(y) by LFUZZY_0:def 5;
               thus {f(y)  where y is Element of X:P[y]}
               ={g(y) where y is Element of X:P[y]} from FraenkelF'(A2);
             end;
           hence thesis;
         end;
       then
A1:    for r being Element of FL st P[r] holds F(r) = G(r);
       thus {F(r) where r is Element of FuzzyLattice [:X,X:]: P[r] }
       = {G(r) where r is Element of FuzzyLattice [:X,X:]: P[r]}
       from FraenkelF'R(A1);
     end;
     
th27:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
  {"\/"({R. [x,y] "/\" @(r). [y,z] where
   y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
    where r is Element of FuzzyLattice [:X,X:]: r in Q}
  = {(R(#)@r). [x,z] where r is Element of FuzzyLattice [:X,X:]: r in Q}
    proof
       let R be RMembership_Func of X,X;
       let Q be Subset of FuzzyLattice [:X,X:];
       let x,z be Element of X;
       set FL = FuzzyLattice [:X,X:];
       defpred P[Element of FL] means $1 in Q;
       deffunc F(Element of FL)
       = "\/"({R. [x,y] "/\" @($1). [y,z] where
          y is Element of X:not contradiction} ,RealPoset [. 0,1 .]);
       deffunc G(Element of FL) = (R (#) @($1)). [x,z];
A1:    for r being Element of FL st P[r] holds F(r) = G(r) by LFUZZY_0:22;
       thus {F(r) where r is Element of FuzzyLattice [:X,X:]:P[r]}
       = {G(r) where r is Element of FuzzyLattice [:X,X:]: P[r]}
         from FraenkelF'R(A1);        
    end;
    
th28:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
  {(R(#)@r). [x,z] where r is Element of FuzzyLattice [:X,X:]: r in Q}
  = pi({(R(#)@r) where r is Element of FuzzyLattice [:X,X:]: r in Q}, [x,z])
    proof
       let R be RMembership_Func of X,X;
       let Q be Subset of FuzzyLattice [:X,X:];
       let x,z be Element of X;
       set FL = FuzzyLattice [:X,X:],
       A= {(R(#)@r). [x,z] where r is Element of FuzzyLattice [:X,X:]: r in Q},
       B= pi({(R(#)@r) where r is Element of FL: r in Q}, [x,z]);
       thus A c= B
         proof
           let a be set;
           assume a in A;then
           consider r being Element of FL such that
A1:        a = (R(#)@r). [x,z] & r in Q;
           (R(#)@r) in {(R(#)@r') where r' is Element of FL: r' in Q} by A1;
           hence thesis by CARD_3:def 6,A1;
         end;
       thus B c= A
         proof
           let b be set;
           assume b in B;then
           consider f be Function such that
A2:        f in {(R(#)@r') where r' is Element of FL: r' in Q} & b = f. [x,z]
            by CARD_3:def 6;
           consider r being Element of FL such that
A3:           f = R (#) @r & r in Q by A2;
           thus b in A by A2,A3;
         end;
    end;
    
th29:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:],
  x,z being Element of X holds
     "\/"({"\/"({R. [x,y] "/\" r. [y,z]
      where r is Element of FuzzyLattice [:X,X:]: r in Q} ,RealPoset [. 0,1 .])
      where y is Element of X:not contradiction},RealPoset [. 0,1 .])
  =  "\/"({"\/"({R. [x,y] "/\" r'. [y,z]
      where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
     where r' is Element of FuzzyLattice [:X,X:]: r' in Q},RealPoset [. 0,1 .])
    proof
       let R be RMembership_Func of X,X;
       let Q be Subset of FuzzyLattice [:X,X:];
       let x,z be Element of X;
       set FL = FuzzyLattice [:X,X:], RP = RealPoset [. 0,1 .];
       defpred P[Element of X] means not contradiction;
       defpred Q[Element of FuzzyLattice [:X,X:]] means $1 in Q;
       deffunc F1(Element of X,Element of FuzzyLattice [:X,X:])
       = R. [x,$1] "/\" $2. [$1,z];
       deffunc F2(Element of X,Element of FuzzyLattice [:X,X:])
       = R. [x,$1] "/\" $2. [$1,z];
A1:    for y being Element of X, r being Element of FL st P[y] & Q[r]
       holds F1(y,r) = F2(y,r);
       thus  "\/"({ "\/"({F1(y,r) where r is Element of FL: Q[r]}, RP)
                                  where y is Element of X: P[y] }, RP)
           = "\/"({ "\/"({F2(y',r') where y' is Element of X: P[y']}, RP)
                           where r' is Element of FL: Q[r'] }, RP)
                           from SupCommutativity(A1);       
    end;

theorem th30:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:] holds
  R (#) @("\/"(Q,FuzzyLattice [:X,X:]))
  = "\/"({R (#) @r where r is Element of FuzzyLattice [:X,X:]:r in Q},
  FuzzyLattice [:X,X:])
   proof
     let R be RMembership_Func of X,X;
     let Q be Subset of FuzzyLattice [:X,X:];
     set FL = FuzzyLattice [:X,X:],
         RP = RealPoset [. 0,1 .];
     ("\/"({R (#) @r where r is Element of FL:r in Q},FL))
         = @("\/"({R (#) @r where r is Element of FL:r in Q},FL))
       by LFUZZY_0:def 5;then
     reconsider F = ("\/"({R (#) @r where r is Element of FL:r in Q},FL)) as
     RMembership_Func of X,X;
     for x,z being Element of X holds (R (#) @("\/"(Q,FL))). [x,z] =  F. [x,z]
       proof
         let x,z be Element of X;
AA:         {(R(#)@r)  where r is Element of FL: r in Q}
            c= the carrier of FuzzyLattice [:X,X:]
           proof
             let t be set;
             assume t in {(R(#)@r)  where r is Element of FL: r in Q};then
             consider r being Element of FuzzyLattice [:X,X:] such that
A4:          t = (R(#)@r) & r in Q;
             ([:X,X:],(R(#)@r))@ = (R(#)@r) by LFUZZY_0:def 6;
             hence t in the carrier of FuzzyLattice [:X,X:] by A4;
           end;
         thus (R (#) @("\/"(Q,FL))). [x,z]
         = "\/"({R. [x,y] "/\" (@("\/"(Q,FL))). [y,z] where y is Element of X:
               not contradiction},RP) by LFUZZY_0:22
         .= "\/"({R. [x,y] "/\" "\/"(pi(Q, [y,z]), RP) where y is Element of X:
               not contradiction},RP) by th23
         .= "\/"(
         {"\/"({R. [x,y] "/\" b where b is Element of RP:b in pi(Q,[y,z])} ,RP)
         where y is Element of X:not contradiction},RP) by th24
         .= "\/"(
         {"\/"({R. [x,y] "/\" r. [y,z]
         where r is Element of FL: r in Q} ,RP)
         where y is Element of X:not contradiction},RP) by th25
         .= "\/"(
         {"\/"({R. [x,y] "/\" r. [y,z]
         where y is Element of X:not contradiction} ,RP)
         where r is Element of FL: r in Q},RP) by th29
         .= "\/"(
         {"\/"({R. [x,y] "/\" @r. [y,z] where
             y is Element of X:not contradiction} ,RP)
         where r is Element of FL: r in Q},RP) by th26
         .= "\/"({(R(#)@r). [x,z] where r is Element of FL: r in Q},RP) by th27
         .= "\/"(pi({(R(#)@r) where r is Element of FL: r in Q}, [x,z]),RP)
         by th28
         .= F. [x,z] by th22,AA;         
       end;
     hence thesis by Th1;
   end;
   
theorem th31:
  for R being RMembership_Func of X,X,
  Q being Subset of FuzzyLattice [:X,X:] holds
  @("\/"(Q,FuzzyLattice [:X,X:])) (#) R
  = "\/"({@r (#) R  where r is Element of FuzzyLattice [:X,X:]:r in Q},
  FuzzyLattice [:X,X:])
   proof
     let R be RMembership_Func of X,X;
     let Q be Subset of FuzzyLattice [:X,X:];
     set FL = FuzzyLattice [:X,X:],
         RP = RealPoset [. 0,1 .];
     ("\/"({@r (#) R where r is Element of FL:r in Q},FL))
         = @("\/"({@r (#) R where r is Element of FL:r in Q},FL))
       by LFUZZY_0:def 5;then
     reconsider F = ("\/"({@r (#) R  where r is Element of FL:r in Q},FL)) as
     RMembership_Func of X,X;
     for x,z being Element of X holds (@("\/"(Q,FL)) (#) R). [x,z] =  F. [x,z]
       proof
         let x,z be Element of X;
ZZ:      {(@r(#)R)  where r is Element of FL: r in Q}
            c= the carrier of FuzzyLattice [:X,X:]
           proof
             let t be set;
             assume t in {(@r(#)R)  where r is Element of FL: r in Q};then
             consider r being Element of FuzzyLattice [:X,X:] such that
A4:          t = (@r(#)R) & r in Q;
             ([:X,X:],(@r(#)R))@ = (@r(#)R) by LFUZZY_0:def 6;
             hence t in the carrier of FuzzyLattice [:X,X:] by A4;
           end;
B1:      {(@("\/"(Q,FL))). [x,y] "/\" R. [y,z] where y is Element of X:
               not contradiction}         
         = {"\/"(pi(Q, [x,y]), RP) "/\" R. [y,z] where y is Element of X:
               not contradiction}
          proof
            defpred P[Element of X] means
            not contradiction;
            deffunc F(Element of X) = (@("\/"(Q,FL))). [x,$1] "/\" R. [$1,z];
            deffunc G(Element of X) = "\/"(pi(Q, [x,$1]), RP) "/\" R. [$1,z];
            for y being Element of X holds
             (@("\/"(Q,FuzzyLattice [:X,X:]))). [x,y] "/\" R. [y,z]
              = "\/"(pi(Q, [x,y]), RealPoset [. 0,1 .]) "/\" R. [y,z]
              proof
                let y be Element of X;
                (@("\/"(Q,FuzzyLattice [:X,X:]))). [x,y]
                 = (("\/"(Q,FuzzyLattice [:X,X:]))). [x,y] by LFUZZY_0:def 5
                .= "\/"(pi(Q, [x,y]), RealPoset [. 0,1 .]) by th22;
               hence thesis;
              end;
             then
B11:         for y being Element of X holds F(y) = G(y);
             thus {F(y) where y is Element of X: P[y]}
              = {G(y') where y' is Element of X: P[y']} from FraenkelF'(B11);
           end;
B2:      {"\/"(pi(Q, [x,y]), RP) "/\" R. [y,z]
             where y is Element of X:not contradiction}
         = {"\/"({b "/\" R. [y',z]
            where b is Element of RP:b in pi(Q,[x,y])} ,RP)
                where y' is Element of X:not contradiction}
           proof
            defpred P[Element of X] means  not contradiction;
            deffunc F(Element of X) =  "\/"(pi(Q, [x,$1]),RP) "/\" R. [$1,z];
            deffunc G(Element of X) =  "\/"({b "/\" R. [$1,z]
                      where b is Element of RP: b in pi(Q,[x,$1])} ,RP);
            for y being Element of X holds
            "\/"(pi(Q, [x,y]), RealPoset [. 0,1 .]) "/\" R. [y,z]
            = "\/"({b "/\" R. [y,z]
                 where b is Element of RP:b in pi(Q,[x,y])} ,RP)
              proof
               let y be Element of X;
B21:           FuzzyLattice [:X,X:]
               = (RealPoset [. 0,1 .]) |^ [:X,X:] by LFUZZY_0:def 4
               .= product ([:X,X:] --> RealPoset [. 0,1 .]) by YELLOW_1:def 5;
               reconsider Q as Subset of
               product ([:X,X:] --> RealPoset [. 0,1 .]) by B21;
               pi(Q, [x,y]) is Subset of RealPoset [. 0,1 .] by FUNCOP_1:13;
               hence thesis by LFUZZY_0:15;
              end;
            then
B22:        for y being Element of X holds F(y) = G (y);
            {F(y) where y is Element of X:P[y]}
            = {G(y') where y' is Element of X:P[y']} from FraenkelF'(B22);
            hence thesis;
          end;
B3:      {"\/"({b "/\" R. [y,z] where b is Element of RP:b in pi(Q,[x,y])} ,RP)
                                where y is Element of X:not contradiction}
         = {"\/"({r. [x,y'] "/\" R. [y',z]
                               where r is Element of FL: r in Q} ,RP)
                               where y' is Element of X:not contradiction}
      proof
      defpred P[Element of X] means not contradiction;
      deffunc F(Element of X) =
      "\/"({b "/\" R. [$1,z] where b is Element of RP: b in pi(Q,[x,$1])} ,RP);
      deffunc G(Element of X) =
      "\/"({r. [x,$1] "/\" R. [$1,z] where r is Element of FL: r in Q} ,RP);
      for y being Element of X holds
      "\/"({b "/\" R. [y,z] where b is Element of RP: b in pi(Q,[x,y])} ,RP)
      = "\/"({r. [x,y] "/\" R. [y,z] where r is Element of FL: r in Q} ,RP)
        proof
          let y be Element of X;
          set A = {b "/\" R. [y,z] where b is Element of RP: b in pi(Q,[x,y])},
          B = {r. [x,y] "/\" R. [y,z] where r is Element of FL: r in Q};
          A = B
           proof
             thus A c= B
               proof
                 let a be set;
                 assume a in A;then
                 consider b be Element of RP such that
B3A2:              a = b "/\" R. [y,z] & b in pi(Q,[x,y]);
                 consider f be Function such that
B3A3:              f in Q & b = f. [x,y] by CARD_3:def 6,B3A2;
                 thus thesis by B3A2,B3A3;
               end;
             thus B c= A
             proof
               let a be set;
               assume a in B;then
               consider r being Element of FL such that
A4:               a = r. [x,y] "/\" R. [y,z] & r in Q;
               r. [x,y] in pi(Q,[x,y]) by CARD_3:def 6,A4;
               hence thesis by A4;
             end;
           end;
          hence thesis;
        end;then
A1:   for y being Element of X holds F(y) = G (y);
      thus {F(y) where y is Element of X:P[y]}
      = {G(y) where y is Element of X:P[y]} from FraenkelF'(A1);
    end;    
B4:      "\/"({"\/"({r. [x,y] "/\" R. [y,z]
         where r is Element of FL: r in Q} ,RP)
         where y is Element of X:not contradiction},RP)
       = "\/"({"\/"({r'. [x,y] "/\" R. [y,z]
         where y is Element of X:not contradiction} ,RP)
         where r' is Element of FL: r' in Q},RP)
    proof
       defpred P[Element of X] means not contradiction;
       defpred Q[Element of FuzzyLattice [:X,X:]] means $1 in Q;
       deffunc F1(Element of X,Element of FuzzyLattice [:X,X:])
       = $2. [x,$1] "/\" R. [$1,z];
       deffunc F2(Element of X,Element of FuzzyLattice [:X,X:])
       = $2. [x,$1] "/\" R. [$1,z];
A1:    for y being Element of X, r being Element of FL st P[y] & Q[r]
       holds F1(y,r) = F2(y,r);
       thus  "\/"({ "\/"({F1(y,r) where r is Element of FL: Q[r]}, RP)
                                  where y is Element of X: P[y] }, RP)
           = "\/"({ "\/"({F2(y',r') where y' is Element of X: P[y']}, RP)
                           where r' is Element of FL: Q[r'] }, RP)
                           from SupCommutativity(A1);       
    end;
B5:      {"\/"({r. [x,y] "/\" R. [y,z]
         where y is Element of X:not contradiction} ,RP)
         where r is Element of FL: r in Q} =
         {"\/"({@r'. [x,y] "/\" R. [y,z]
         where y is Element of X:not contradiction} ,RP)
         where r' is Element of FL: r' in Q}
     proof
       defpred P[Element of FL] means $1 in Q;
       deffunc F(Element of FL)
       = "\/"({$1. [x,y] "/\" R. [y,z]
         where y is Element of X:not contradiction} ,RealPoset [. 0,1 .]);
       deffunc G(Element of FL)
       = "\/"({@($1). [x,y] "/\" R. [y,z]
         where y is Element of X:not contradiction} ,RealPoset [. 0,1 .]);
       for r being Element of FL st r in Q holds
         "\/"({r. [x,y] "/\" R. [y,z]
           where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
         = "\/"({@r. [x,y] "/\" R. [y,z]
           where y is Element of X:not contradiction} ,RealPoset [. 0,1 .])
         proof
           let r be Element of FL;
           assume r in Q;
           {r. [x,y] "/\" R. [y,z]  where y is Element of X:not contradiction}
           ={@r. [x,y] "/\" R. [y,z] where y is Element of X:not contradiction}
             proof
               defpred P[Element of X] means not contradiction;
               deffunc f(Element of X) = r. [x,$1] "/\" R. [$1,z];
               deffunc g(Element of X) = @r. [x,$1] "/\" R. [$1,z];
A2:            for y being Element of X holds f(y) = g(y) by LFUZZY_0:def 5;
               thus {f(y)  where y is Element of X:P[y]}
               ={g(y) where y is Element of X:P[y]} from FraenkelF'(A2);
             end;
           hence thesis;
         end;
       then
A1:    for r being Element of FL st P[r] holds F(r) = G(r);
       thus {F(r)  where r is Element of FuzzyLattice [:X,X:]: P[r] }
       = {G(r) where r is Element of FuzzyLattice [:X,X:]: P[r]}
       from FraenkelF'R(A1);
     end;
B6:      {"\/"({@r. [x,y] "/\" R. [y,z] where
             y is Element of X:not contradiction} ,RP)
         where r is Element of FL: r in Q}
         = {(@r'(#)R). [x,z] where r' is Element of FL: r' in Q}
    proof
       defpred P[Element of FL] means $1 in Q;
       deffunc F(Element of FL)
       = "\/"({@($1). [x,y] "/\" R. [y,z] where
          y is Element of X:not contradiction} ,RealPoset [. 0,1 .]);
       deffunc G(Element of FL) = (@($1)(#)R). [x,z];
A1:    for r being Element of FL st P[r] holds F(r) = G(r) by LFUZZY_0:22;
       thus {F(r) where r is Element of FuzzyLattice [:X,X:]:P[r]}
       = {G(r) where r is Element of FuzzyLattice [:X,X:]: P[r]}
         from FraenkelF'R(A1);        
    end;
B7:      {(@r(#)R). [x,z] where r is Element of FL: r in Q}
         = pi({(@r(#)R) where r is Element of FL: r in Q}, [x,z])
    proof
       set A= {(@r(#)R). [x,z] where r is Element of FL: r in Q},
       B= pi({(@r(#)R) where r is Element of FL: r in Q}, [x,z]);
       thus A c= B
         proof
           let a be set;
           assume a in A;then
           consider r being Element of FL such that
A1:        a = (@r(#)R). [x,z] & r in Q;
           (@r(#)R) in {(@r'(#)R) where r' is Element of FL: r' in Q} by A1;
           hence thesis by CARD_3:def 6,A1;
         end;
       thus B c= A
         proof
           let b be set;
           assume b in B;then
           consider f be Function such that
A2:        f in {(@r'(#)R) where r' is Element of FL: r' in Q} & b = f. [x,z]
            by CARD_3:def 6;
           consider r being Element of FL such that
A3:           f = (@r(#)R) & r in Q by A2;
           thus b in A by A2,A3;
         end;
    end;
         thus (@("\/"(Q,FL)) (#) R). [x,z]
         = "\/"({(@("\/"(Q,FL))). [x,y] "/\" R. [y,z] where y is Element of X:
               not contradiction},RP) by LFUZZY_0:22
         .= F. [x,z] by B1,B2,B3,B4,B5,B6,B7,th22,ZZ;        
       end;
     hence thesis by Th1;
   end;

theorem th32:
  for R being RMembership_Func of X,X holds
  (TrCl R)(#)(TrCl R)
  = "\/"({(i iter R) (#) (j iter R)
       where i is Nat, j is Nat:i > 0 & j > 0},FuzzyLattice [:X,X:])
    proof
      let R be RMembership_Func of X,X;
      set Q = {n iter R where n is Nat : n > 0},
      FL = FuzzyLattice [:X,X:];
A1:   "\/"(Q,FL) = @"\/"(Q,FL) by LFUZZY_0:def 5;
AA:      Q c= the carrier of FL
        proof
          let q be set; assume q in Q; then
          consider i being Nat such that
A4:       q = (i iter R)  & i > 0;
             ([:X,X:],(i iter R) )@ = i iter R by LFUZZY_0:def 6;
             hence q in the carrier of FuzzyLattice [:X,X:] by A4;
        end;
A3:   {@r (#) (TrCl R) where r is Element of FL:r in Q} =
      {"\/"({@r' (#) @s where s is Element of FL:s in Q},FL)
      where r' is Element of FL : r' in Q}
        proof
          set A = {@r (#) (TrCl R) where r is Element of FL:r in Q},
          B = {"\/"({@r' (#) @s where s is Element of FL:s in Q},FL)
                 where r' is Element of FL : r' in Q};
          thus A c= B
            proof
              let a be set; assume a in A; then
              consider r being Element of FL such that
A31:          a = @r (#) (TrCl R) & r in Q;
              a = @r (#) @"\/"(Q,FL) by A1,Def12,A31
              .= "\/"({@r (#) @s where s is Element of FL:s in Q},FL)
                by AA,th30;
              hence thesis by A31;              
            end;
          thus B c= A
            proof
              let a be set; assume a in B; then
              consider r being Element of FL such that
A32:          a = "\/"({@r (#) @s where s is Element of FL:s in Q},FL)
                   & r in Q;
              a = @r (#) @"\/"(Q,FL) by AA,th30,A32
              .= @r (#) (TrCl R) by A1,Def12;
              hence thesis by A32;
            end;
        end;
A5:   {@r (#) @s  where r is Element of FL,s is Element of FL:r in Q & s in Q}
      = {(i iter R) (#) (j iter R) where i is Nat, j is Nat:i > 0 & j > 0}
        proof
          set A = {@r (#) @s
                 where r is Element of FL,s is Element of FL:r in Q & s in Q},
              B = {(i iter R) (#) (j iter R)
                 where i is Nat, j is Nat:i > 0 & j > 0};
          thus A c= B
            proof
              let a be set;  assume a in A; then
              consider r,s being Element of FL such that
A51:          a = @r (#) @s & r in Q & s in Q;
              consider i being Nat such that
A52:          r = i iter R & i > 0 by A51;
              consider j being Nat such that
A53:          s = j iter R & j > 0 by A51;
A54:          r = @r & s = @s by LFUZZY_0:def 5;
              thus thesis by A51,A54,A52,A53;
            end;
          thus B c= A
            proof
              let b be set; assume b in B; then
              consider i,j being Nat such that
A55:          b = (i iter R) (#) (j iter R) & i > 0 & j > 0;
A56:          (i iter R) in Q & (j iter R) in Q by A55;
A57:          (i iter R) = ([:X,X:],(i iter R))@ &
              (j iter R) = ([:X,X:],(j iter R))@ by LFUZZY_0:def 6;
              reconsider r = i iter R as Element of FL by A57;
              reconsider s = j iter R as Element of FL by A57;
              @r = r & @s = s by LFUZZY_0:def 5;
              hence thesis by A56,A55;
            end;
        end;    
      deffunc f(Element of FL,Element of FL) = ([:X,X:],@$1 (#) @$2)@;
      defpred P[Element of FL] means $1 in Q;
      defpred R[Element of FL] means $1 in Q;
A6:   {"\/"({@r (#) @s where s is Element of FL : s in Q},FL)
                         where r is Element of FL : r in Q}
      = {"\/"({([:X,X:],@r' (#) @s')@ where s' is Element of FL : s' in Q},FL)
                                    where r' is Element of FL : r' in Q}
        proof
          defpred P[Element of FL] means $1 in Q;
          deffunc F(Element of FL) =
          "\/"({@$1 (#) @s where s is Element of FL : s in Q},FL);
          deffunc G(Element of FL) =
          "\/"({([:X,X:],@$1 (#) @s)@ where s is Element of FL : s in Q},FL);
          for r being Element of FL holds
          "\/"({@r (#) @s where s is Element of FL : s in Q},FL)
          = "\/"({([:X,X:],@r (#) @s)@ where s is Element of FL : s in Q},FL)
            proof
              let r be Element of FL;
              {@r (#) @s where s is Element of FL : s in Q}
              = {([:X,X:],@r (#) @s)@ where s is Element of FL : s in Q}
                proof
                  defpred P[Element of FL] means $1 in Q;
                  deffunc f(Element of FL) = @r (#) @$1;
                  deffunc g(Element of FL) = ([:X,X:],@r (#) @$1)@;
A62:              for s being Element of FL holds f(s) = g(s)
                    by LFUZZY_0:def 6;
                  {f(s) where s is Element of FL : P[s]} =
                  {g(s) where s is Element of FL : P[s]} from FraenkelF'(A62);
                  hence thesis;
                end;
              hence thesis;
            end;then
A61:      for r being Element of FL holds F(r) = G(r);
          {F(r) where r is Element of FL : P[r]}
          = {G(r)     where r is Element of FL : P[r]} from FraenkelF'(A61);
          hence thesis;
        end;                           
A7:   {([:X,X:],@r (#) @s)@  where r is Element of FL,
         s is Element of FL:r in Q & s in Q}
      = {@r (#) @s  where r is Element of FL,
          s is Element of FL:r in Q & s in Q}
        proof
          defpred P[Element of FL,Element of FL] means $1 in Q & $2 in Q;
          deffunc F(Element of FL,Element of FL) = ([:X,X:],@$1 (#) @$2)@;
          deffunc G(Element of FL,Element of FL) = @$1 (#) @$2;
A71:      for r being Element of FL, s being Element of FL holds
          F(r,s) = G(r,s) by LFUZZY_0:def 6;
          {F(r,s) where r is Element of FL,s is Element of FL:P[r,s]}
          ={G(r,s) where r is Element of FL,s is Element of FL:P[r,s]}
          from  FraenkelF''(A71);
          hence thesis;
        end;
      thus (TrCl R)(#)(TrCl R)
       = @"\/"(Q,FL) (#) (TrCl R) by A1,Def12
      .= "\/"({"\/"({f(r,s) where s is Element of FL:R[s]},FL)
                           where r is Element of FL :P[r]},FL) by A6,A3,AA,th31
      .= "\/"({f(r,s) where r is Element of FL, s is Element of FL:
               P[r] & R[s]},FL) from SupDistributivity
      .= "\/"({(i iter R) (#) (j iter R)  where i is Nat, j is Nat:
               i > 0 & j > 0},FL) by A5,A7;
    end;
    
definition
  let X be non empty set;
  let R be RMembership_Func of X,X;
  cluster TrCl R -> transitive;
  coherence
    proof
      set FL = FuzzyLattice [:X,X:], RP = RealPoset [. 0,1 .],
      A = {(i iter R) (#) (j iter R)
                   where i is Nat, j is Nat:i > 0 & j > 0};
      for c being Element of [:X,X:] holds
      ((TrCl R)(#)(TrCl R)).c <= (TrCl R).c
        proof
          let c be Element of [:X,X:];
AA:          A c= the carrier of FuzzyLattice [:X,X:]
           proof
             let t be set;
             assume t in A;then
             consider i,j being Nat such that
A4:          t = (i iter R) (#) (j iter R) & i > 0 & j >0;
             ([:X,X:],((i iter R) (#) (j iter R)))@ = 
             (i iter R) (#) (j iter R) by LFUZZY_0:def 6;
             hence t in the carrier of FuzzyLattice [:X,X:] by A4;
           end;
B2:          ((TrCl R)(#)(TrCl R)).c
          = "\/"(A,FL).c by th32
          .= "\/"(pi(A,c),RP) by AA,th22;
          (TrCl R).c is_>=_than pi(A,c)
            proof
              for b being Element of RP st b in pi(A,c) holds b <<= (TrCl R).c
                proof
                  let b be Element of RP;
                  assume b in pi(A,c);then
                  consider f be Function such that
C1:               f in A & b = f.c by CARD_3:def 6;
                  consider i,j being Nat such that
C2:               f = (i iter R) (#) (j iter R) & i > 0 & j > 0 by C1;
C3:               i+j > 0 by ANALOAF:2,C2;
C4:               f = (i+j) iter R by C2,th19;
                  reconsider f as RMembership_Func of X,X by C2;
                  f c= TrCl R by th33,C3,C4;then
                  f.c <= (TrCl R).c by Def1;
                  hence thesis by C1,LFUZZY_0:3;
                end;
              hence thesis by LATTICE3:def 9;
            end;
          then
          "\/"(pi(A,c),RP) <<= (TrCl R).c by YELLOW_0:32;
          hence thesis by B2,LFUZZY_0:3;          
        end;
      then (TrCl R)(#)(TrCl R) c= (TrCl R) by Def1;
      hence thesis by Def7;
    end;    
end;

theorem th36:
  for R being RMembership_Func of X,X, n being natural number
  st R is transitive & n > 0 holds n iter R c= R
    proof
      let R be RMembership_Func of X,X;
      let n be natural number;
      assume
A1:   R is transitive & n > 0; then
A6:   R (#) R c= R by Def7;
      defpred P[Nat] means $1 iter R c= R;
      reconsider n as non empty Nat by A1,ORDINAL2:def 21;
      1 iter R = R by th20;then      
A2:   P[1] by FUZZY14;
A3:   for k being non empty Nat st P[k] holds P[k+1]
        proof
          let k be non empty Nat; assume
A4:       P[k];
          R c= R by FUZZY14;then
          k iter R (#) R c= R(#)R by A4,FUZZY430;then
          (k+1) iter R c= R(#)R by th17;
          hence thesis by A6,FUZZY15;          
        end;
      for k being non empty Nat holds P[k] from Ind_from_1(A2,A3);
      then P[n];
      hence thesis;
    end;

theorem th34:
  for R being RMembership_Func of X,X st R is transitive holds
  R = TrCl R
   proof
     let R be RMembership_Func of X,X;
     assume
A0:  R is transitive;
A1:  R c= TrCl R by th35;
     TrCl R c= R
       proof
         for c being Element of [:X,X:] holds (TrCl R).c <= R.c
           proof
             let c be Element of [:X,X:];
             set Q = {n iter R where n is Nat : n > 0},
             FL = FuzzyLattice [:X,X:],
             RP = RealPoset [. 0,1 .]; 
AS:          Q c= the carrier of FuzzyLattice [:X,X:]
               proof
               let t be set;
               assume t in Q;then
               consider i being Nat such that
A4:            t = (i iter R)  & i > 0;
               ([:X,X:],(i iter R))@ = 
               (i iter R) by LFUZZY_0:def 6;
               hence t in the carrier of FuzzyLattice [:X,X:] by A4;
               end;
A5:          (TrCl R).c = "\/"(Q,FL).c by Def12
                        .= "\/"(pi(Q,c),RP) by AS,th22;
             for b being Element of RP st b in pi(Q,c) holds b <<= R.c
               proof
                 let b be Element of RP; assume b in pi(Q,c); then
                 consider f being Function such that
A2:              f in Q & b = f.c by CARD_3:def 6;
                 consider n be Nat such that
A3:              f = n iter R & n>0 by A2;
                 n iter R c= R by A0,A3,th36;then
                 (n iter R).c <= R.c by Def1;
                 hence thesis by LFUZZY_0:3,A2,A3;                 
               end;then
             R.c is_>=_than pi(Q,c) by LATTICE3:def 9;then
             (TrCl R).c <<= R.c by YELLOW_0:32,A5;
             hence thesis by LFUZZY_0:3; 
           end;
         hence thesis by Def1;
       end;
     hence thesis by FUZZY13,A1;
   end;

theorem th36:
  for R,S being RMembership_Func of X,X, n being natural number st R c= S holds
  n iter R c= n iter S
    proof
      let R,S be RMembership_Func of X,X;
      let n be natural number; assume
A0:   R c= S;
      defpred P[natural number] means $1 iter R c= $1 iter S;
      0 iter R = Imf(X,X) by th18
      .= 0 iter S by th18;then
A1:   P[0] by FUZZY13;
A3:   for k being natural number st P[k] holds P[k+1]
        proof
          let k be natural number; assume
AA:       P[k];
          (k iter R) (#) R = (k+1) iter R & (k iter S) (#) S = (k+1) iter S
         by th17;
          hence thesis by AA,FUZZY430,A0;
        end;
      for k being natural number holds P[k] from  Nat_Ind(A1,A3);
      hence thesis;
    end;

theorem
  for R,S being RMembership_Func of X,X st S is transitive & R c= S holds
  TrCl R c= S
    proof
      let R,S be RMembership_Func of X,X; assume
A0:   S is transitive & R c= S;
      TrCl R c= TrCl S
        proof
          for c being Element of [:X,X:] holds (TrCl R).c <= (TrCl S).c
            proof
              let c be Element of [:X,X:];
              set Q = {n iter R where n is Nat : n > 0},
              FL = FuzzyLattice [:X,X:],
              RP = RealPoset [. 0,1 .]; 
AS:          Q c= the carrier of FuzzyLattice [:X,X:]
           proof
             let t be set;
             assume t in Q;then
             consider i being Nat such that
A4:          t = (i iter R) & i > 0;
             ([:X,X:],(i iter R))@ = 
             (i iter R) by LFUZZY_0:def 6;
             hence t in the carrier of FuzzyLattice [:X,X:] by A4;
           end;
A1:           (TrCl R).c = "\/"(Q,FL).c by Def12
                        .= "\/"(pi(Q,c),RP) by AS,th22;
              (TrCl S).c is_>=_than pi(Q,c)
                proof
                  for b being Element of RP st b in pi(Q,c) holds
                      b <<= (TrCl S).c
                    proof
                      let b be Element of RP; assume
                      b in pi(Q,c);then
                      consider f being Function such that
A2:                   f in Q & b = f.c by CARD_3:def 6;
                      consider n be Nat such that
A3:                   f = n iter R & n>0 by A2;
                      n iter R c= n iter S & n iter S c= TrCl S
                        by A0,th36,th33,A3;
                      then
                      n iter R c= TrCl S by FUZZY15;
                      then
                      (n iter R).c <= (TrCl S).c by Def1;
                      hence thesis by LFUZZY_0:3,A3,A2;                      
                    end;
                  hence thesis by LATTICE3:def 9;
                end;
              then "\/"(pi(Q,c),RP) <<= (TrCl S).c by YELLOW_0:32;
              hence thesis by LFUZZY_0:3,A1;
            end;
          hence thesis by Def1;
        end;
      hence thesis by th34,A0;
    end;

Back to top