:: ZF_COLLA semantic presentation

begin

definition
let E be ( ( non empty ) ( non empty ) set ) ;
let A be ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ;
func Collapse (E,A) -> ( ( ) ( ) set ) means :: ZF_COLLA:def 1
ex L being ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) st
( it : ( ( Function-like V29(E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,A : ( ( non empty ) ( non empty ) set ) ) ) ( Relation-like E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) -defined A : ( ( non empty ) ( non empty ) set ) -valued Function-like V29(E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,A : ( ( non empty ) ( non empty ) set ) ) ) Element of K6(K7(E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,A : ( ( non empty ) ( non empty ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) = { d : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) where d is ( ( ) ( ) Element of E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ) : for d1 being ( ( ) ( ) Element of E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ) st d1 : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) in d : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) holds
ex B being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st
( B : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) in dom L : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) : ( ( ) ( epsilon-transitive epsilon-connected ordinal ) set ) & d1 : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) in union {(L : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) . B : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) ) : ( ( ) ( ) set ) } : ( ( ) ( non empty ) set ) : ( ( ) ( ) set ) )
}
& dom L : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) : ( ( ) ( epsilon-transitive epsilon-connected ordinal ) set ) = A : ( ( non empty ) ( non empty ) set ) & ( for B being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) in A : ( ( non empty ) ( non empty ) set ) holds
L : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) . B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) : ( ( ) ( ) set ) = { d1 : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) where d1 is ( ( ) ( ) Element of E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ) : for d being ( ( ) ( ) Element of E : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ) st d : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) in d1 : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds
ex C being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st
( C : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) in dom (L : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) | B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( Relation-like ) ( T-Sequence-like Relation-like rng b1 : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) : ( ( ) ( ) set ) -valued Function-like ) set ) : ( ( ) ( epsilon-transitive epsilon-connected ordinal ) set ) & d : ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) in union {((L : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) | B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( Relation-like ) ( T-Sequence-like Relation-like rng b1 : ( ( T-Sequence-like Relation-like Function-like ) ( T-Sequence-like Relation-like Function-like ) T-Sequence) : ( ( ) ( ) set ) -valued Function-like ) set ) . C : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) } : ( ( ) ( non empty ) set ) : ( ( ) ( ) set ) )
}
) );
end;

theorem :: ZF_COLLA:1
for E being ( ( non empty ) ( non empty ) set )
for A being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) holds Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) = { d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) where d is ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) : for d1 being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) st d1 : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) holds
ex B being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st
( B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) in A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) & d1 : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) )
}
;

theorem :: ZF_COLLA:2
for E being ( ( non empty ) ( non empty ) set )
for d being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds
( ( for d1 being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds not d1 : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) ) iff d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,{} : ( ( ) ( empty epsilon-transitive epsilon-connected ordinal T-Sequence-like c=-linear natural Function-like functional V32() V33() V34() V35() V36() V37() V38() ) set ) ) : ( ( ) ( ) set ) ) ;

theorem :: ZF_COLLA:3
for E being ( ( non empty ) ( non empty ) set )
for A being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal)
for d being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds
( d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) /\ E : ( ( non empty ) ( non empty ) set ) : ( ( ) ( ) set ) c= Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) iff d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,(succ A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal ) set ) ) : ( ( ) ( ) set ) ) ;

theorem :: ZF_COLLA:4
for E being ( ( non empty ) ( non empty ) set )
for A, B being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) c= B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) holds
Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) c= Collapse (E : ( ( non empty ) ( non empty ) set ) ,B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) ;

theorem :: ZF_COLLA:5
for E being ( ( non empty ) ( non empty ) set )
for d being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) ex A being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) ;

theorem :: ZF_COLLA:6
for E being ( ( non empty ) ( non empty ) set )
for A being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal)
for d9, d being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) st d9 : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) & d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) holds
( d9 : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) & ex B being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st
( B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) in A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) & d9 : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in Collapse (E : ( ( non empty ) ( non empty ) set ) ,B : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) ) ) ;

theorem :: ZF_COLLA:7
for E being ( ( non empty ) ( non empty ) set )
for A being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) holds Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) c= E : ( ( non empty ) ( non empty ) set ) ;

theorem :: ZF_COLLA:8
for E being ( ( non empty ) ( non empty ) set ) ex A being ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) st E : ( ( non empty ) ( non empty ) set ) = Collapse (E : ( ( non empty ) ( non empty ) set ) ,A : ( ( ordinal ) ( epsilon-transitive epsilon-connected ordinal ) Ordinal) ) : ( ( ) ( ) set ) ;

theorem :: ZF_COLLA:9
for E being ( ( non empty ) ( non empty ) set ) ex f being ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) st
( dom f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) : ( ( ) ( ) set ) = E : ( ( non empty ) ( non empty ) set ) & ( for d being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) . d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) : ( ( ) ( ) set ) = f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) .: d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) : ( ( ) ( ) set ) ) ) ;

definition
let f be ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) ;
let X, Y be ( ( ) ( ) set ) ;
pred f is_epsilon-isomorphism_of X,Y means :: ZF_COLLA:def 2
( dom f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) : ( ( ) ( ) set ) = X : ( ( non empty ) ( non empty ) set ) & rng f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) : ( ( ) ( ) set ) = Y : ( ( Function-like V29(f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,X : ( ( non empty ) ( non empty ) set ) ) ) ( Relation-like f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) -defined X : ( ( non empty ) ( non empty ) set ) -valued Function-like V29(f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,X : ( ( non empty ) ( non empty ) set ) ) ) Element of K6(K7(f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,X : ( ( non empty ) ( non empty ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) & f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) is one-to-one & ( for x, y being ( ( ) ( ) set ) st x : ( ( ) ( ) set ) in X : ( ( non empty ) ( non empty ) set ) & y : ( ( ) ( ) set ) in X : ( ( non empty ) ( non empty ) set ) holds
( ex Z being ( ( ) ( ) set ) st
( Z : ( ( ) ( ) set ) = y : ( ( ) ( ) set ) & x : ( ( ) ( ) set ) in Z : ( ( ) ( ) set ) ) iff ex Z being ( ( ) ( ) set ) st
( f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) . y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = Z : ( ( ) ( ) set ) & f : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) . x : ( ( ) ( ) set ) : ( ( ) ( ) set ) in Z : ( ( ) ( ) set ) ) ) ) );
end;

definition
let X, Y be ( ( ) ( ) set ) ;
pred X,Y are_epsilon-isomorphic means :: ZF_COLLA:def 3
ex f being ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) st f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) is_epsilon-isomorphism_of X : ( ( ZF-formula-like ) ( Relation-like Function-like V47() ZF-formula-like ) M6(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) ,Y : ( ( non empty ) ( non empty ) set ) ;
end;

theorem :: ZF_COLLA:10
for E being ( ( non empty ) ( non empty ) set )
for f being ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) st dom f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) : ( ( ) ( ) set ) = E : ( ( non empty ) ( non empty ) set ) & ( for d being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) . d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) : ( ( ) ( ) set ) = f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) .: d : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) : ( ( ) ( ) set ) ) holds
rng f : ( ( Relation-like Function-like ) ( Relation-like Function-like ) Function) : ( ( ) ( ) set ) is epsilon-transitive ;

theorem :: ZF_COLLA:11
for E being ( ( non empty ) ( non empty ) set ) st E : ( ( non empty ) ( non empty ) set ) |= the_axiom_of_extensionality : ( ( ZF-formula-like ) ( Relation-like K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) -defined K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) -valued Function-like V47() ZF-formula-like ) M7(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) holds
for u, v being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) st ( for w being ( ( ) ( ) Element of E : ( ( non empty ) ( non empty ) set ) ) holds
( w : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in u : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) iff w : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) in v : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) ) ) holds
u : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) = v : ( ( ) ( ) Element of b1 : ( ( non empty ) ( non empty ) set ) ) ;

theorem :: ZF_COLLA:12
for E being ( ( non empty ) ( non empty ) set ) st E : ( ( non empty ) ( non empty ) set ) |= the_axiom_of_extensionality : ( ( ZF-formula-like ) ( Relation-like K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) -defined K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) -valued Function-like V47() ZF-formula-like ) M7(K32() : ( ( ) ( non empty epsilon-transitive epsilon-connected ordinal V32() V33() V34() V35() V36() V37() V38() ) Element of K6(K28() : ( ( ) ( V32() V33() V34() V38() ) set ) ) : ( ( ) ( ) set ) ) )) holds
ex X being ( ( ) ( ) set ) st
( X : ( ( ) ( ) set ) is epsilon-transitive & E : ( ( non empty ) ( non empty ) set ) ,X : ( ( ) ( ) set ) are_epsilon-isomorphic ) ;