The Mizar article:

Predicate Calculus for Boolean Valued Functions. Part X

by
Shunichi Kobayashi

Received November 15, 1999

Copyright (c) 1999 Association of Mizar Users

MML identifier: BVFUNC18
[ MML identifier index ]


environ

 vocabulary FUNCT_2, MARGREL1, PARTIT1, EQREL_1, BVFUNC_2, ZF_LANG, BVFUNC_1,
      T_1TOPSP;
 notation XBOOLE_0, SUBSET_1, FRAENKEL, MARGREL1, VALUAT_1, EQREL_1, SETWISEO,
      BVFUNC_1, BVFUNC_2;
 constructors SETWISEO, BVFUNC_2, BVFUNC_1;
 clusters SUBSET_1, MARGREL1, VALUAT_1, AMI_1, XBOOLE_0;
 definitions BVFUNC_1;
 theorems T_1TOPSP, MARGREL1, BVFUNC_1, BVFUNC_2, BVFUNC13, VALUAT_1;

begin :: Chap. 1  Predicate Calculus

reserve Y for non empty set;

canceled 3;

theorem  for a being Element of Funcs(Y,BOOLEAN),
G being Subset of PARTITIONS(Y),
A,B,C being a_partition of Y holds
All('not' Ex(a,A,G),B,G) '<' 'not' Ex(All(a,B,G),A,G)
proof
  let a be Element of Funcs(Y,BOOLEAN);
  let G be Subset of PARTITIONS(Y);
  let A,B,C be a_partition of Y;
A1:Ex(a,A,G) = B_SUP(a,CompF(A,G)) by BVFUNC_2:def 10;
A2:All('not' Ex(a,A,G),B,G) = B_INF('not' Ex(a,A,G),CompF(B,G))
     by BVFUNC_2:def 9;
A3:for y being Element of Y holds
   (    (for x being Element of Y st x in EqClass(y,CompF(B,G)) holds
         Pj('not' Ex(a,A,G),x)=TRUE) implies
        Pj(B_INF('not' Ex(a,A,G),CompF(B,G)),y) = TRUE ) &
   (not (for x being Element of Y st x in EqClass(y,CompF(B,G)) holds
         Pj('not' Ex(a,A,G),x)=TRUE) implies
        Pj(B_INF('not' Ex(a,A,G),CompF(B,G)),y) = FALSE)
     by BVFUNC_1:def 19;

A4:All(a,B,G) = B_INF(a,CompF(B,G)) by BVFUNC_2:def 9;
A5:Ex(All(a,B,G),A,G) = B_SUP(All(a,B,G),CompF(A,G))
    by BVFUNC_2:def 10;

    let z be Element of Y;
    assume A6:Pj(All('not' Ex(a,A,G),B,G),z)=TRUE;
A7:z in EqClass(z,CompF(B,G)) &
      EqClass(z,CompF(B,G)) in CompF(B,G)
      by T_1TOPSP:def 1;
    now assume
      not (for x being Element of Y st x in EqClass(z,CompF(B,G)) holds
       Pj('not' Ex(a,A,G),x)=TRUE);then
      Pj(B_INF('not' Ex(a,A,G),CompF(B,G)),z) = FALSE by A3;then
      Pj(All('not' Ex(a,A,G),B,G),z)=FALSE by A2;then
      Pj(All('not' Ex(a,A,G),B,G),z)<>TRUE by MARGREL1:43;
      hence contradiction by A6;
    end;then
    for x being Element of Y st x in EqClass(z,CompF(B,G)) holds
       Pj('not' Ex(a,A,G),x)=TRUE;then
    Pj('not' Ex(a,A,G),z)=TRUE by A7;then
    'not' Pj(Ex(a,A,G),z)=TRUE by VALUAT_1:def 5;then
    Pj(Ex(a,A,G),z)='not' TRUE by MARGREL1:40;then
    A8:Pj(Ex(a,A,G),z)=FALSE by MARGREL1:41;
    now assume
      ex x being Element of Y st
            x in EqClass(z,CompF(A,G)) & Pj(a,x)=TRUE;then
      Pj(B_SUP(a,CompF(A,G)),z) = TRUE by BVFUNC_1:def 20;then
      Pj(Ex(a,A,G),z)=TRUE by A1;
      hence contradiction by A8,MARGREL1:43;
    end;then
    A9:for x being Element of Y st
            x in EqClass(z,CompF(A,G)) holds Pj(a,x)<>TRUE;

    for x being Element of Y st
            x in EqClass(z,CompF(A,G)) holds Pj(All(a,B,G),x)<>TRUE
    proof
      let x be Element of Y;
      assume x in EqClass(z,CompF(A,G));then
      A10:Pj(a,x)<>TRUE by A9;
      x in EqClass(x,CompF(B,G)) & EqClass(x,CompF(B,G)) in CompF(B,G)
        by T_1TOPSP:def 1;then
      ex y being Element of Y st y in EqClass(x,CompF(B,G)) &
         Pj(a,y)<>TRUE by A10;then
      Pj(B_INF(a,CompF(B,G)),x) = FALSE by BVFUNC_1:def 19;then
      Pj(All(a,B,G),x)=FALSE by A4;then
      Pj(All(a,B,G),x)<>TRUE by MARGREL1:43;
      hence thesis;
    end;then
    not (ex x being Element of Y st
            x in EqClass(z,CompF(A,G)) & Pj(All(a,B,G),x)=TRUE);then
    Pj(B_SUP(All(a,B,G),CompF(A,G)),z) = FALSE by BVFUNC_1:def 20;then
    Pj(Ex(All(a,B,G),A,G),z)=FALSE by A5;then
    'not' Pj(Ex(All(a,B,G),A,G),z)=TRUE by MARGREL1:41;
    hence thesis by VALUAT_1:def 5;
end;

Lm1:for a being Element of Funcs(Y,BOOLEAN),G being Subset of PARTITIONS(Y),
A,B,C being a_partition of Y st G is independent holds
Ex('not' All(a,A,G),B,G) '<' Ex('not' All(a,B,G),A,G) by BVFUNC13:34;

canceled 2;

theorem
for a being Element of Funcs(Y,BOOLEAN),G being Subset of PARTITIONS(Y),
A,B,C being a_partition of Y
st G is independent & G={A,B,C} & A<>B & B<>C & C<>A holds
Ex('not' All(a,A,G),B,G) = Ex('not' All(a,B,G),A,G)
proof
  let a be Element of Funcs(Y,BOOLEAN);
  let G be Subset of PARTITIONS(Y);
  let A,B,C be a_partition of Y;
  assume A1:G is independent & G={A,B,C} & A<>B & B<>C & C<>A;then
A2:Ex('not' All(a,A,G),B,G) '<' Ex('not' All(a,B,G),A,G) by Lm1;
  Ex('not' All(a,B,G),A,G) '<' Ex('not' All(a,A,G),B,G) by A1,Lm1;
  hence thesis by A2,BVFUNC_1:18;
end;

canceled 6;

theorem
for a being Element of Funcs(Y,BOOLEAN),G being Subset of PARTITIONS(Y),
A,B,C being a_partition of Y
st G is independent & G={A,B,C} & A<>B & B<>C & C<>A holds
All('not' Ex(a,A,G),B,G) = All('not' Ex(a,B,G),A,G)
proof
  let a be Element of Funcs(Y,BOOLEAN);
  let G be Subset of PARTITIONS(Y);
  let A,B,C be a_partition of Y;
  assume A1:G is independent & G={A,B,C} & A<>B & B<>C & C<>A;then
A2:All('not' Ex(a,A,G),B,G) '<' All('not' Ex(a,B,G),A,G) by BVFUNC13:41;
  All('not' Ex(a,B,G),A,G) '<' All('not' Ex(a,A,G),B,G) by A1,BVFUNC13:41;
  hence thesis by A2,BVFUNC_1:18;
end;

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