let W be Universe; :: thesis: for L being DOMAIN-Sequence of W st omega in W & ( for a, b being Ordinal of W st a in b holds
L . a c= L . b ) & ( for a being Ordinal of W st a <> {} & a is limit_ordinal holds
L . a = Union (L | a) ) holds
for H being ZF-formula ex phi being Ordinal-Sequence of W st
( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

let L be DOMAIN-Sequence of W; :: thesis: ( omega in W & ( for a, b being Ordinal of W st a in b holds
L . a c= L . b ) & ( for a being Ordinal of W st a <> {} & a is limit_ordinal holds
L . a = Union (L | a) ) implies for H being ZF-formula ex phi being Ordinal-Sequence of W st
( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) ) )

assume that
A1: omega in W and
A2: for a, b being Ordinal of W st a in b holds
L . a c= L . b and
A3: for a being Ordinal of W st a <> {} & a is limit_ordinal holds
L . a = Union (L | a) ; :: thesis: for H being ZF-formula ex phi being Ordinal-Sequence of W st
( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

set M = Union L;
A4: union (rng L) = Union L by CARD_3:def 4;
defpred S1[ ZF-formula] means ex phi being Ordinal-Sequence of W st
( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= $1 iff L . a,f |= $1 ) ) );
A5: dom L = On W by Def2;
A6: for H being ZF-formula st H is universal & S1[ the_scope_of H] holds
S1[H]
proof
deffunc H1( Ordinal of W, Ordinal-Sequence) -> Ordinal of W = union ($2,$1);
let H be ZF-formula; :: thesis: ( H is universal & S1[ the_scope_of H] implies S1[H] )
set x0 = bound_in H;
set H9 = the_scope_of H;
defpred S2[ set , set ] means ex f being Function of VAR,(Union L) st
( $1 = f & ( ex m being Element of Union L st
( m in L . $2 & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( $2 = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) );
assume H is universal ; :: thesis: ( not S1[ the_scope_of H] or S1[H] )
then A7: H = All ((bound_in H),(the_scope_of H)) by ZF_LANG:44;
A8: for h being Element of Funcs (VAR,(Union L)) ex a being Ordinal of W st S2[h,a]
proof
let h be Element of Funcs (VAR,(Union L)); :: thesis: ex a being Ordinal of W st S2[h,a]
reconsider f = h as Element of Funcs (VAR,(Union L)) ;
reconsider f = f as Function of VAR,(Union L) ;
now :: thesis: ex a being Ordinal of W st S2[h,a]
per cases ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) or ex m being Element of Union L st Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ;
suppose for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ; :: thesis: ex a being Ordinal of W st S2[h,a]
hence ex a being Ordinal of W st S2[h,a] ; :: thesis: verum
end;
suppose A9: ex m being Element of Union L st Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ; :: thesis: ex a being Ordinal of W st S2[h,a]
thus ex a being Ordinal of W st S2[h,a] :: thesis: verum
proof
consider m being Element of Union L such that
A10: Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) by A9;
consider X being set such that
A11: m in X and
A12: X in rng L by A4, TARSKI:def 4;
consider x being object such that
A13: x in dom L and
A14: X = L . x by A12, FUNCT_1:def 3;
reconsider x = x as Ordinal by A13;
reconsider b = x as Ordinal of W by A5, A13, ORDINAL1:def 9;
take b ; :: thesis: S2[h,b]
take f ; :: thesis: ( h = f & ( ex m being Element of Union L st
( m in L . b & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( b = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) )

thus ( h = f & ( ex m being Element of Union L st
( m in L . b & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( b = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) by A10, A11, A14; :: thesis: verum
end;
end;
end;
end;
hence ex a being Ordinal of W st S2[h,a] ; :: thesis: verum
end;
consider rho being Function such that
A15: dom rho = Funcs (VAR,(Union L)) and
A16: for h being Element of Funcs (VAR,(Union L)) ex a being Ordinal of W st
( a = rho . h & S2[h,a] & ( for b being Ordinal of W st S2[h,b] holds
a c= b ) ) from ZF_REFLE:sch 1(A8);
defpred S3[ Ordinal of W, Ordinal of W] means $2 = sup (rho .: (Funcs (VAR,(L . $1))));
A17: for a being Ordinal of W ex b being Ordinal of W st S3[a,b]
proof
let a be Ordinal of W; :: thesis: ex b being Ordinal of W st S3[a,b]
set X = rho .: (Funcs (VAR,(L . a)));
A18: rho .: (Funcs (VAR,(L . a))) c= W
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in rho .: (Funcs (VAR,(L . a))) or x in W )
assume x in rho .: (Funcs (VAR,(L . a))) ; :: thesis: x in W
then consider h being object such that
h in dom rho and
A19: h in Funcs (VAR,(L . a)) and
A20: x = rho . h by FUNCT_1:def 6;
Funcs (VAR,(L . a)) c= Funcs (VAR,(Union L)) by Th16, FUNCT_5:56;
then reconsider h = h as Element of Funcs (VAR,(Union L)) by A19;
ex a being Ordinal of W st
( a = rho . h & ex f being Function of VAR,(Union L) st
( h = f & ( ex m being Element of Union L st
( m in L . a & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( a = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) & ( for b being Ordinal of W st ex f being Function of VAR,(Union L) st
( h = f & ( ex m being Element of Union L st
( m in L . b & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( b = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) holds
a c= b ) ) by A16;
hence x in W by A20; :: thesis: verum
end;
Funcs (omega,(L . a)) in W by A1, CLASSES2:61;
then A21: card (Funcs (omega,(L . a))) in card W by CLASSES2:1;
( card VAR = card omega & card (L . a) = card (L . a) ) by Th17, CARD_1:5;
then card (Funcs (VAR,(L . a))) = card (Funcs (omega,(L . a))) by FUNCT_5:61;
then card (rho .: (Funcs (VAR,(L . a)))) in card W by A21, CARD_1:67, ORDINAL1:12;
then rho .: (Funcs (VAR,(L . a))) in W by A18, CLASSES1:1;
then reconsider b = sup (rho .: (Funcs (VAR,(L . a)))) as Ordinal of W by Th19;
take b ; :: thesis: S3[a,b]
thus S3[a,b] ; :: thesis: verum
end;
consider si being Ordinal-Sequence of W such that
A22: for a being Ordinal of W holds S3[a,si . a] from ZF_REFLE:sch 2(A17);
deffunc H2( Ordinal of W, Ordinal of W) -> Element of W = succ ((si . (succ $1)) \/ $2);
consider ksi being Ordinal-Sequence of W such that
A23: ksi . (0-element_of W) = si . (0-element_of W) and
A24: for a being Ordinal of W holds ksi . (succ a) = H2(a,ksi . a) and
A25: for a being Ordinal of W st a <> 0-element_of W & a is limit_ordinal holds
ksi . a = H1(a,ksi | a) from ZF_REFLE:sch 3();
defpred S4[ Ordinal] means si . $1 c= ksi . $1;
given phi being Ordinal-Sequence of W such that A26: phi is increasing and
A27: phi is continuous and
A28: for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= the_scope_of H iff L . a,f |= the_scope_of H ) ; :: thesis: S1[H]
A29: ksi is increasing
proof
let A be Ordinal; :: according to ORDINAL2:def 12 :: thesis: for b1 being set holds
( not A in b1 or not b1 in dom ksi or ksi . A in ksi . b1 )

let B be Ordinal; :: thesis: ( not A in B or not B in dom ksi or ksi . A in ksi . B )
assume that
A30: A in B and
A31: B in dom ksi ; :: thesis: ksi . A in ksi . B
A in dom ksi by A30, A31, ORDINAL1:10;
then reconsider a = A, b = B as Ordinal of W by A31, ORDINAL1:def 9;
defpred S5[ Ordinal of W] means ( a in $1 implies ksi . a in ksi . $1 );
A32: for c being Ordinal of W st S5[c] holds
S5[ succ c]
proof
let c be Ordinal of W; :: thesis: ( S5[c] implies S5[ succ c] )
assume that
A33: ( a in c implies ksi . a in ksi . c ) and
A34: a in succ c ; :: thesis: ksi . a in ksi . (succ c)
A35: a c= c by A34, ORDINAL1:22;
A36: ( ksi . a in ksi . c or ksi . a = ksi . c )
proof
per cases ( a <> c or a = c ) ;
suppose a <> c ; :: thesis: ( ksi . a in ksi . c or ksi . a = ksi . c )
then a c< c by A35;
hence ( ksi . a in ksi . c or ksi . a = ksi . c ) by A33, ORDINAL1:11; :: thesis: verum
end;
suppose a = c ; :: thesis: ( ksi . a in ksi . c or ksi . a = ksi . c )
hence ( ksi . a in ksi . c or ksi . a = ksi . c ) ; :: thesis: verum
end;
end;
end;
A37: ksi . c c= (si . (succ c)) \/ (ksi . c) by XBOOLE_1:7;
( ksi . (succ c) = succ ((si . (succ c)) \/ (ksi . c)) & (si . (succ c)) \/ (ksi . c) in succ ((si . (succ c)) \/ (ksi . c)) ) by A24, ORDINAL1:22;
hence ksi . a in ksi . (succ c) by A37, A36, ORDINAL1:10, ORDINAL1:12; :: thesis: verum
end;
A38: for b being Ordinal of W st b <> 0-element_of W & b is limit_ordinal & ( for c being Ordinal of W st c in b holds
S5[c] ) holds
S5[b]
proof
ksi . (succ a) = succ ((si . (succ a)) \/ (ksi . a)) by A24;
then (si . (succ a)) \/ (ksi . a) in ksi . (succ a) by ORDINAL1:6;
then A39: ksi . a in ksi . (succ a) by ORDINAL1:12, XBOOLE_1:7;
let b be Ordinal of W; :: thesis: ( b <> 0-element_of W & b is limit_ordinal & ( for c being Ordinal of W st c in b holds
S5[c] ) implies S5[b] )

assume that
A40: b <> 0-element_of W and
A41: b is limit_ordinal and
for c being Ordinal of W st c in b holds
S5[c] and
A42: a in b ; :: thesis: ksi . a in ksi . b
( succ a in dom ksi & succ a in b ) by A41, A42, ORDINAL1:28, ORDINAL4:34;
then A43: ksi . (succ a) in rng (ksi | b) by FUNCT_1:50;
ksi . b = union ((ksi | b),b) by A25, A40, A41
.= Union (ksi | b) by Th14
.= union (rng (ksi | b)) by CARD_3:def 4 ;
hence ksi . a in ksi . b by A43, A39, TARSKI:def 4; :: thesis: verum
end;
A44: S5[ 0-element_of W] by ORDINAL4:33;
for c being Ordinal of W holds S5[c] from ZF_REFLE:sch 4(A44, A32, A38);
then ksi . a in ksi . b by A30;
hence ksi . A in ksi . B ; :: thesis: verum
end;
A45: 0-element_of W = {} by ORDINAL4:33;
A46: ksi is continuous
proof
let A be Ordinal; :: according to ORDINAL2:def 13 :: thesis: for b1 being set holds
( not A in dom ksi or A = 0 or not A is limit_ordinal or not b1 = ksi . A or b1 is_limes_of ksi | A )

let B be Ordinal; :: thesis: ( not A in dom ksi or A = 0 or not A is limit_ordinal or not B = ksi . A or B is_limes_of ksi | A )
assume that
A47: A in dom ksi and
A48: A <> 0 and
A49: A is limit_ordinal and
A50: B = ksi . A ; :: thesis: B is_limes_of ksi | A
A c= dom ksi by A47, ORDINAL1:def 2;
then A51: dom (ksi | A) = A by RELAT_1:62;
reconsider a = A as Ordinal of W by A47, ORDINAL1:def 9;
A52: B = union ((ksi | a),a) by A25, A45, A48, A49, A50
.= Union (ksi | a) by Th14
.= union (rng (ksi | a)) by CARD_3:def 4 ;
A53: B c= sup (ksi | A)
proof
let C be Ordinal; :: according to ORDINAL1:def 5 :: thesis: ( not C in B or C in sup (ksi | A) )
assume C in B ; :: thesis: C in sup (ksi | A)
then consider X being set such that
A54: C in X and
A55: X in rng (ksi | A) by A52, TARSKI:def 4;
rng (ksi | A) c= rng ksi by RELAT_1:70;
then X in rng ksi by A55;
then reconsider X = X as Ordinal ;
X in sup (ksi | A) by A55, ORDINAL2:19;
hence C in sup (ksi | A) by A54, ORDINAL1:10; :: thesis: verum
end;
A56: ksi | A is increasing by A29, ORDINAL4:15;
A57: sup (ksi | A) c= B
proof
let C be Ordinal; :: according to ORDINAL1:def 5 :: thesis: ( not C in sup (ksi | A) or C in B )
assume C in sup (ksi | A) ; :: thesis: C in B
then consider D being Ordinal such that
A58: D in rng (ksi | A) and
A59: C c= D by ORDINAL2:21;
consider x being object such that
A60: x in dom (ksi | A) and
A61: D = (ksi | A) . x by A58, FUNCT_1:def 3;
reconsider x = x as Ordinal by A60;
A62: succ x in A by A49, A60, ORDINAL1:28;
then A63: (ksi | A) . (succ x) in rng (ksi | A) by A51, FUNCT_1:def 3;
x in succ x by ORDINAL1:6;
then D in (ksi | A) . (succ x) by A51, A56, A61, A62;
then D in B by A52, A63, TARSKI:def 4;
hence C in B by A59, ORDINAL1:12; :: thesis: verum
end;
sup (ksi | A) is_limes_of ksi | A by A48, A49, A51, A56, ORDINAL4:8;
hence B is_limes_of ksi | A by A53, A57, XBOOLE_0:def 10; :: thesis: verum
end;
A64: for a being Ordinal of W st a <> 0-element_of W & a is limit_ordinal holds
si . a c= sup (si | a)
proof
let a be Ordinal of W; :: thesis: ( a <> 0-element_of W & a is limit_ordinal implies si . a c= sup (si | a) )
defpred S5[ object ] means $1 in Free ('not' (the_scope_of H));
assume that
A65: a <> 0-element_of W and
A66: a is limit_ordinal ; :: thesis: si . a c= sup (si | a)
A67: si . a = sup (rho .: (Funcs (VAR,(L . a)))) by A22;
let A be Ordinal; :: according to ORDINAL1:def 5 :: thesis: ( not A in si . a or A in sup (si | a) )
assume A in si . a ; :: thesis: A in sup (si | a)
then consider B being Ordinal such that
A68: B in rho .: (Funcs (VAR,(L . a))) and
A69: A c= B by A67, ORDINAL2:21;
consider x being object such that
A70: x in dom rho and
A71: x in Funcs (VAR,(L . a)) and
A72: B = rho . x by A68, FUNCT_1:def 6;
reconsider h = x as Element of Funcs (VAR,(Union L)) by A15, A70;
consider a1 being Ordinal of W such that
A73: a1 = rho . h and
A74: ex f being Function of VAR,(Union L) st
( h = f & ( ex m being Element of Union L st
( m in L . a1 & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( a1 = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) and
A75: for b being Ordinal of W st ex f being Function of VAR,(Union L) st
( h = f & ( ex m being Element of Union L st
( m in L . b & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( b = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) holds
a1 c= b by A16;
consider f being Function of VAR,(Union L) such that
A76: h = f and
A77: ( ex m being Element of Union L st
( m in L . a1 & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( a1 = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) by A74;
defpred S6[ object , object ] means for a being Ordinal of W st f . $1 in L . a holds
f . $2 in L . a;
A78: now :: thesis: ( Free ('not' (the_scope_of H)) <> {} implies ex x being Ordinal of W st
( x in a & ( for y being Variable st y in Free ('not' (the_scope_of H)) holds
f . y in L . x ) ) )
A79: for x, y being object holds
( S6[x,y] or S6[y,x] )
proof
let x, y be object ; :: thesis: ( S6[x,y] or S6[y,x] )
given a being Ordinal of W such that A80: ( f . x in L . a & not f . y in L . a ) ; :: thesis: S6[y,x]
let b be Ordinal of W; :: thesis: ( f . y in L . b implies f . x in L . b )
assume A81: f . y in L . b ; :: thesis: f . x in L . b
( a in b or a = b or b in a ) by ORDINAL1:14;
then ( L . a c= L . b or L . b c= L . a ) by A2;
hence f . x in L . b by A80, A81; :: thesis: verum
end;
assume Free ('not' (the_scope_of H)) <> {} ; :: thesis: ex x being Ordinal of W st
( x in a & ( for y being Variable st y in Free ('not' (the_scope_of H)) holds
f . y in L . x ) )

then A82: Free ('not' (the_scope_of H)) <> {} ;
A83: ( L . a = Union (L | a) & Union (L | a) = union (rng (L | a)) ) by A3, A45, A65, A66, CARD_3:def 4;
A84: for x, y, z being object st S6[x,y] & S6[y,z] holds
S6[x,z] ;
consider z being object such that
A85: ( z in Free ('not' (the_scope_of H)) & ( for y being object st y in Free ('not' (the_scope_of H)) holds
S6[z,y] ) ) from CARD_2:sch 2(A82, A79, A84);
reconsider z = z as Variable by A85;
A86: dom (L | a) c= a by RELAT_1:58;
A87: ex s being Function st
( f = s & dom s = VAR & rng s c= L . a ) by A71, A76, FUNCT_2:def 2;
then f . z in rng f by FUNCT_1:def 3;
then consider X being set such that
A88: f . z in X and
A89: X in rng (L | a) by A87, A83, TARSKI:def 4;
consider x being object such that
A90: x in dom (L | a) and
A91: X = (L | a) . x by A89, FUNCT_1:def 3;
A92: (L | a) . x = L . x by A90, FUNCT_1:47;
reconsider x = x as Ordinal by A90;
a in On W by ORDINAL1:def 9;
then x in On W by A90, A86, ORDINAL1:10;
then reconsider x = x as Ordinal of W by ORDINAL1:def 9;
take x = x; :: thesis: ( x in a & ( for y being Variable st y in Free ('not' (the_scope_of H)) holds
f . y in L . x ) )

thus x in a by A90, A86; :: thesis: for y being Variable st y in Free ('not' (the_scope_of H)) holds
f . y in L . x

let y be Variable; :: thesis: ( y in Free ('not' (the_scope_of H)) implies f . y in L . x )
assume y in Free ('not' (the_scope_of H)) ; :: thesis: f . y in L . x
hence f . y in L . x by A85, A88, A91, A92; :: thesis: verum
end;
now :: thesis: ( Free ('not' (the_scope_of H)) = {} implies ex b being Element of W st
( b in a & ( for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
f . x1 in L . b ) ) )
assume A93: Free ('not' (the_scope_of H)) = {} ; :: thesis: ex b being Element of W st
( b in a & ( for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
f . x1 in L . b ) )

take b = 0-element_of W; :: thesis: ( b in a & ( for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
f . x1 in L . b ) )

thus b in a by A45, A65, ORDINAL3:8; :: thesis: for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
f . x1 in L . b

thus for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
f . x1 in L . b by A93; :: thesis: verum
end;
then consider c being Ordinal of W such that
A94: c in a and
A95: for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
f . x1 in L . c by A78;
A96: si . c = sup (rho .: (Funcs (VAR,(L . c)))) by A22;
( c in dom si & dom (si | a) = (dom si) /\ a ) by ORDINAL4:34, RELAT_1:61;
then A97: c in dom (si | a) by A94, XBOOLE_0:def 4;
si . c = (si | a) . c by A94, FUNCT_1:49;
then si . c in rng (si | a) by A97, FUNCT_1:def 3;
then A98: si . c in sup (si | a) by ORDINAL2:19;
deffunc H3( object ) -> set = f . $1;
set e = the Element of L . c;
deffunc H4( object ) -> Element of L . c = the Element of L . c;
consider v being Function such that
A99: ( dom v = VAR & ( for x being object st x in VAR holds
( ( S5[x] implies v . x = H3(x) ) & ( not S5[x] implies v . x = H4(x) ) ) ) ) from PARTFUN1:sch 1();
A100: rng v c= L . c
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in rng v or x in L . c )
assume x in rng v ; :: thesis: x in L . c
then consider y being object such that
A101: y in dom v and
A102: x = v . y by FUNCT_1:def 3;
reconsider y = y as Variable by A99, A101;
( y in Free ('not' (the_scope_of H)) or not y in Free ('not' (the_scope_of H)) ) ;
then ( ( x = f . y & f . y in L . c ) or x = the Element of L . c ) by A95, A99, A102;
hence x in L . c ; :: thesis: verum
end;
then reconsider v = v as Function of VAR,(L . c) by A99, FUNCT_2:def 1, RELSET_1:4;
A103: v in Funcs (VAR,(L . c)) by A99, A100, FUNCT_2:def 2;
Funcs (VAR,(L . c)) c= Funcs (VAR,(Union L)) by Th16, FUNCT_5:56;
then reconsider v9 = v as Element of Funcs (VAR,(Union L)) by A103;
consider a2 being Ordinal of W such that
A104: a2 = rho . v9 and
A105: ex f being Function of VAR,(Union L) st
( v9 = f & ( ex m being Element of Union L st
( m in L . a2 & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( a2 = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) and
A106: for b being Ordinal of W st ex f being Function of VAR,(Union L) st
( v9 = f & ( ex m being Element of Union L st
( m in L . b & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( b = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) holds
a2 c= b by A16;
consider f9 being Function of VAR,(Union L) such that
A107: v9 = f9 and
A108: ( ex m being Element of Union L st
( m in L . a2 & Union L,f9 / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( a2 = 0-element_of W & ( for m being Element of Union L holds not Union L,f9 / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) by A105;
A109: v = (Union L) ! v by Th16, ZF_LANG1:def 1;
A110: now :: thesis: ( ex m being Element of Union L st
( m in L . a1 & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) implies a1 = a2 )
given m being Element of Union L such that A111: m in L . a1 and
A112: Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ; :: thesis: a1 = a2
A113: now :: thesis: for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
(f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1
let x1 be Variable; :: thesis: ( x1 in Free ('not' (the_scope_of H)) implies (f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1 )
A114: (f / ((bound_in H),m)) . (bound_in H) = m by FUNCT_7:128;
A115: ( x1 <> bound_in H implies ( (f / ((bound_in H),m)) . x1 = f . x1 & (((Union L) ! v) / ((bound_in H),m)) . x1 = ((Union L) ! v) . x1 ) ) by FUNCT_7:32;
assume x1 in Free ('not' (the_scope_of H)) ; :: thesis: (f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1
hence (f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1 by A99, A109, A114, A115, FUNCT_7:128; :: thesis: verum
end;
then Union L,((Union L) ! v) / ((bound_in H),m) |= 'not' (the_scope_of H) by A112, ZF_LANG1:75;
then consider m9 being Element of Union L such that
A116: ( m9 in L . a2 & Union L,f9 / ((bound_in H),m9) |= 'not' (the_scope_of H) ) by A109, A107, A108;
now :: thesis: for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
(f / ((bound_in H),m9)) . x1 = (f9 / ((bound_in H),m9)) . x1
let x1 be Variable; :: thesis: ( x1 in Free ('not' (the_scope_of H)) implies (f / ((bound_in H),m9)) . x1 = (f9 / ((bound_in H),m9)) . x1 )
A117: (f / ((bound_in H),m9)) . (bound_in H) = m9 by FUNCT_7:128;
A118: ( x1 <> bound_in H implies ( (f / ((bound_in H),m9)) . x1 = f . x1 & (((Union L) ! v) / ((bound_in H),m9)) . x1 = ((Union L) ! v) . x1 ) ) by FUNCT_7:32;
assume x1 in Free ('not' (the_scope_of H)) ; :: thesis: (f / ((bound_in H),m9)) . x1 = (f9 / ((bound_in H),m9)) . x1
hence (f / ((bound_in H),m9)) . x1 = (f9 / ((bound_in H),m9)) . x1 by A99, A109, A107, A117, A118, FUNCT_7:128; :: thesis: verum
end;
then A119: a1 c= a2 by A75, A76, A116, ZF_LANG1:75;
a2 c= a1 by A109, A106, A111, A112, A113, ZF_LANG1:75;
hence a1 = a2 by A119; :: thesis: verum
end;
now :: thesis: ( ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) implies a1 = a2 )
assume A120: for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ; :: thesis: a1 = a2
now :: thesis: for m being Element of Union L holds not Union L,((Union L) ! v) / ((bound_in H),m) |= 'not' (the_scope_of H)
let m be Element of Union L; :: thesis: not Union L,((Union L) ! v) / ((bound_in H),m) |= 'not' (the_scope_of H)
now :: thesis: for x1 being Variable st x1 in Free ('not' (the_scope_of H)) holds
(f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1
let x1 be Variable; :: thesis: ( x1 in Free ('not' (the_scope_of H)) implies (f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1 )
A121: (f / ((bound_in H),m)) . (bound_in H) = m by FUNCT_7:128;
A122: ( x1 <> bound_in H implies ( (f / ((bound_in H),m)) . x1 = f . x1 & (((Union L) ! v) / ((bound_in H),m)) . x1 = ((Union L) ! v) . x1 ) ) by FUNCT_7:32;
assume x1 in Free ('not' (the_scope_of H)) ; :: thesis: (f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1
hence (f / ((bound_in H),m)) . x1 = (((Union L) ! v) / ((bound_in H),m)) . x1 by A99, A109, A121, A122, FUNCT_7:128; :: thesis: verum
end;
hence not Union L,((Union L) ! v) / ((bound_in H),m) |= 'not' (the_scope_of H) by A120, ZF_LANG1:75; :: thesis: verum
end;
hence a1 = a2 by A77, A109, A107, A108, A120; :: thesis: verum
end;
then B in rho .: (Funcs (VAR,(L . c))) by A15, A72, A73, A74, A76, A103, A104, A110, FUNCT_1:def 6;
then B in si . c by A96, ORDINAL2:19;
then B in sup (si | a) by A98, ORDINAL1:10;
hence A in sup (si | a) by A69, ORDINAL1:12; :: thesis: verum
end;
A123: for a being Ordinal of W st a <> 0-element_of W & a is limit_ordinal & ( for b being Ordinal of W st b in a holds
S4[b] ) holds
S4[a]
proof
let a be Ordinal of W; :: thesis: ( a <> 0-element_of W & a is limit_ordinal & ( for b being Ordinal of W st b in a holds
S4[b] ) implies S4[a] )

assume that
A124: ( a <> 0-element_of W & a is limit_ordinal ) and
A125: for b being Ordinal of W st b in a holds
si . b c= ksi . b ; :: thesis: S4[a]
thus si . a c= ksi . a :: thesis: verum
proof
A126: si . a c= sup (si | a) by A64, A124;
let A be Ordinal; :: according to ORDINAL1:def 5 :: thesis: ( not A in si . a or A in ksi . a )
assume A in si . a ; :: thesis: A in ksi . a
then consider B being Ordinal such that
A127: B in rng (si | a) and
A128: A c= B by A126, ORDINAL2:21;
consider x being object such that
A129: x in dom (si | a) and
A130: B = (si | a) . x by A127, FUNCT_1:def 3;
reconsider x = x as Ordinal by A129;
A131: a in On W by ORDINAL1:def 9;
x in dom si by A129, RELAT_1:57;
then x in On W ;
then reconsider x = x as Ordinal of W by ORDINAL1:def 9;
A132: si . x = B by A129, A130, FUNCT_1:47;
A133: si . x c= ksi . x by A125, A129;
dom ksi = On W by FUNCT_2:def 1;
then ksi . x in ksi . a by A29, A129, A131;
hence A in ksi . a by A128, A132, A133, ORDINAL1:12, XBOOLE_1:1; :: thesis: verum
end;
end;
A134: for a being Ordinal of W st S4[a] holds
S4[ succ a]
proof
let a be Ordinal of W; :: thesis: ( S4[a] implies S4[ succ a] )
assume si . a c= ksi . a ; :: thesis: S4[ succ a]
( ksi . (succ a) = succ ((si . (succ a)) \/ (ksi . a)) & (si . (succ a)) \/ (ksi . a) in succ ((si . (succ a)) \/ (ksi . a)) ) by A24, ORDINAL1:6;
then si . (succ a) in ksi . (succ a) by ORDINAL1:12, XBOOLE_1:7;
hence si . (succ a) c= ksi . (succ a) by ORDINAL1:def 2; :: thesis: verum
end;
A135: S4[ 0-element_of W] by A23;
A136: for a being Ordinal of W holds S4[a] from ZF_REFLE:sch 4(A135, A134, A123);
A137: now :: thesis: ( bound_in H in Free (the_scope_of H) implies S1[H] )
assume bound_in H in Free (the_scope_of H) ; :: thesis: S1[H]
thus S1[H] :: thesis: verum
proof
take gamma = phi * ksi; :: thesis: ( gamma is increasing & gamma is continuous & ( for a being Ordinal of W st gamma . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

ex f being Ordinal-Sequence st
( f = phi * ksi & f is increasing ) by A26, A29, ORDINAL4:13;
hence ( gamma is increasing & gamma is continuous ) by A27, A29, A46, ORDINAL4:17; :: thesis: for a being Ordinal of W st gamma . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let a be Ordinal of W; :: thesis: ( gamma . a = a & {} <> a implies for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) )

assume that
A138: gamma . a = a and
A139: {} <> a ; :: thesis: for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let f be Function of VAR,(L . a); :: thesis: ( Union L,(Union L) ! f |= H iff L . a,f |= H )
a in dom gamma by ORDINAL4:34;
then A140: phi . (ksi . a) = gamma . a by FUNCT_1:12;
a in dom ksi by ORDINAL4:34;
then A141: a c= ksi . a by A29, ORDINAL4:10;
ksi . a in dom phi by ORDINAL4:34;
then A142: ksi . a c= phi . (ksi . a) by A26, ORDINAL4:10;
then A143: ksi . a = a by A138, A141, A140;
A144: phi . a = a by A138, A142, A141, A140, XBOOLE_0:def 10;
thus ( Union L,(Union L) ! f |= H implies L . a,f |= H ) :: thesis: ( L . a,f |= H implies Union L,(Union L) ! f |= H )
proof
assume A145: Union L,(Union L) ! f |= H ; :: thesis: L . a,f |= H
now :: thesis: for g being Function of VAR,(L . a) st ( for k being Variable st g . k <> f . k holds
bound_in H = k ) holds
L . a,g |= the_scope_of H
let g be Function of VAR,(L . a); :: thesis: ( ( for k being Variable st g . k <> f . k holds
bound_in H = k ) implies L . a,g |= the_scope_of H )

assume A146: for k being Variable st g . k <> f . k holds
bound_in H = k ; :: thesis: L . a,g |= the_scope_of H
now :: thesis: for k being Variable st ((Union L) ! g) . k <> ((Union L) ! f) . k holds
bound_in H = k
let k be Variable; :: thesis: ( ((Union L) ! g) . k <> ((Union L) ! f) . k implies bound_in H = k )
( (Union L) ! f = f & (Union L) ! g = g ) by Th16, ZF_LANG1:def 1;
hence ( ((Union L) ! g) . k <> ((Union L) ! f) . k implies bound_in H = k ) by A146; :: thesis: verum
end;
then Union L,(Union L) ! g |= the_scope_of H by A7, A145, ZF_MODEL:16;
hence L . a,g |= the_scope_of H by A28, A139, A144; :: thesis: verum
end;
hence L . a,f |= H by A7, ZF_MODEL:16; :: thesis: verum
end;
assume that
A147: L . a,f |= H and
A148: not Union L,(Union L) ! f |= H ; :: thesis: contradiction
consider m being Element of Union L such that
A149: not Union L,((Union L) ! f) / ((bound_in H),m) |= the_scope_of H by A7, A148, ZF_LANG1:71;
A150: si . a c= ksi . a by A136;
A151: si . a = sup (rho .: (Funcs (VAR,(L . a)))) by A22;
reconsider h = (Union L) ! f as Element of Funcs (VAR,(Union L)) by FUNCT_2:8;
consider a1 being Ordinal of W such that
A152: a1 = rho . h and
A153: ex f being Function of VAR,(Union L) st
( h = f & ( ex m being Element of Union L st
( m in L . a1 & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( a1 = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) and
for b being Ordinal of W st ex f being Function of VAR,(Union L) st
( h = f & ( ex m being Element of Union L st
( m in L . b & Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) or ( b = 0-element_of W & ( for m being Element of Union L holds not Union L,f / ((bound_in H),m) |= 'not' (the_scope_of H) ) ) ) ) holds
a1 c= b by A16;
A154: (Union L) ! f = f by Th16, ZF_LANG1:def 1;
Union L,((Union L) ! f) / ((bound_in H),m) |= 'not' (the_scope_of H) by A149, ZF_MODEL:14;
then consider m being Element of Union L such that
A155: m in L . a1 and
A156: Union L,((Union L) ! f) / ((bound_in H),m) |= 'not' (the_scope_of H) by A153;
f in Funcs (VAR,(L . a)) by FUNCT_2:8;
then a1 in rho .: (Funcs (VAR,(L . a))) by A15, A152, A154, FUNCT_1:def 6;
then a1 in si . a by A151, ORDINAL2:19;
then L . a1 c= L . a by A2, A143, A150;
then reconsider m9 = m as Element of L . a by A155;
((Union L) ! f) / ((bound_in H),m) = (Union L) ! (f / ((bound_in H),m9)) by A154, Th16, ZF_LANG1:def 1;
then not Union L,(Union L) ! (f / ((bound_in H),m9)) |= the_scope_of H by A156, ZF_MODEL:14;
then not L . a,f / ((bound_in H),m9) |= the_scope_of H by A28, A139, A144;
hence contradiction by A7, A147, ZF_LANG1:71; :: thesis: verum
end;
end;
now :: thesis: ( not bound_in H in Free (the_scope_of H) implies S1[H] )
assume A157: not bound_in H in Free (the_scope_of H) ; :: thesis: S1[H]
thus S1[H] :: thesis: verum
proof
take phi ; :: thesis: ( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

thus ( phi is increasing & phi is continuous ) by A26, A27; :: thesis: for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let a be Ordinal of W; :: thesis: ( phi . a = a & {} <> a implies for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) )

assume A158: ( phi . a = a & {} <> a ) ; :: thesis: for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let f be Function of VAR,(L . a); :: thesis: ( Union L,(Union L) ! f |= H iff L . a,f |= H )
thus ( Union L,(Union L) ! f |= H implies L . a,f |= H ) :: thesis: ( L . a,f |= H implies Union L,(Union L) ! f |= H )
proof
A159: for k being Variable st ((Union L) ! f) . k <> ((Union L) ! f) . k holds
bound_in H = k ;
assume Union L,(Union L) ! f |= H ; :: thesis: L . a,f |= H
then Union L,(Union L) ! f |= the_scope_of H by A7, A159, ZF_MODEL:16;
then L . a,f |= the_scope_of H by A28, A158;
hence L . a,f |= H by A7, A157, ZFMODEL1:10; :: thesis: verum
end;
A160: for k being Variable st f . k <> f . k holds
bound_in H = k ;
assume L . a,f |= H ; :: thesis: Union L,(Union L) ! f |= H
then L . a,f |= the_scope_of H by A7, A160, ZF_MODEL:16;
then Union L,(Union L) ! f |= the_scope_of H by A28, A158;
hence Union L,(Union L) ! f |= H by A7, A157, ZFMODEL1:10; :: thesis: verum
end;
end;
hence S1[H] by A137; :: thesis: verum
end;
A161: for H being ZF-formula st H is conjunctive & S1[ the_left_argument_of H] & S1[ the_right_argument_of H] holds
S1[H]
proof
let H be ZF-formula; :: thesis: ( H is conjunctive & S1[ the_left_argument_of H] & S1[ the_right_argument_of H] implies S1[H] )
assume H is conjunctive ; :: thesis: ( not S1[ the_left_argument_of H] or not S1[ the_right_argument_of H] or S1[H] )
then A162: H = (the_left_argument_of H) '&' (the_right_argument_of H) by ZF_LANG:40;
given fi1 being Ordinal-Sequence of W such that A163: fi1 is increasing and
A164: fi1 is continuous and
A165: for a being Ordinal of W st fi1 . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= the_left_argument_of H iff L . a,f |= the_left_argument_of H ) ; :: thesis: ( not S1[ the_right_argument_of H] or S1[H] )
given fi2 being Ordinal-Sequence of W such that A166: fi2 is increasing and
A167: fi2 is continuous and
A168: for a being Ordinal of W st fi2 . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= the_right_argument_of H iff L . a,f |= the_right_argument_of H ) ; :: thesis: S1[H]
take phi = fi2 * fi1; :: thesis: ( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

ex fi being Ordinal-Sequence st
( fi = fi2 * fi1 & fi is increasing ) by A163, A166, ORDINAL4:13;
hence ( phi is increasing & phi is continuous ) by A163, A164, A167, ORDINAL4:17; :: thesis: for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let a be Ordinal of W; :: thesis: ( phi . a = a & {} <> a implies for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) )

assume that
A169: phi . a = a and
A170: {} <> a ; :: thesis: for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

a in dom fi1 by ORDINAL4:34;
then A171: a c= fi1 . a by A163, ORDINAL4:10;
let f be Function of VAR,(L . a); :: thesis: ( Union L,(Union L) ! f |= H iff L . a,f |= H )
A172: a in dom phi by ORDINAL4:34;
A173: a in dom fi2 by ORDINAL4:34;
A174: now :: thesis: not fi1 . a <> a
assume fi1 . a <> a ; :: thesis: contradiction
then a c< fi1 . a by A171;
then A175: a in fi1 . a by ORDINAL1:11;
A176: phi . a = fi2 . (fi1 . a) by A172, FUNCT_1:12;
fi1 . a in dom fi2 by ORDINAL4:34;
then fi2 . a in fi2 . (fi1 . a) by A166, A175;
hence contradiction by A166, A169, A173, A176, ORDINAL1:5, ORDINAL4:10; :: thesis: verum
end;
then A177: fi2 . a = a by A169, A172, FUNCT_1:12;
thus ( Union L,(Union L) ! f |= H implies L . a,f |= H ) :: thesis: ( L . a,f |= H implies Union L,(Union L) ! f |= H )
proof end;
assume A180: L . a,f |= H ; :: thesis: Union L,(Union L) ! f |= H
then L . a,f |= the_right_argument_of H by A162, ZF_MODEL:15;
then A181: Union L,(Union L) ! f |= the_right_argument_of H by A168, A170, A177;
L . a,f |= the_left_argument_of H by A162, A180, ZF_MODEL:15;
then Union L,(Union L) ! f |= the_left_argument_of H by A165, A170, A174;
hence Union L,(Union L) ! f |= H by A162, A181, ZF_MODEL:15; :: thesis: verum
end;
A182: for H being ZF-formula st H is atomic holds
S1[H]
proof
A183: dom (id (On W)) = On W ;
then reconsider phi = id (On W) as Sequence by ORDINAL1:def 7;
A184: rng (id (On W)) = On W ;
reconsider phi = phi as Ordinal-Sequence ;
reconsider phi = phi as Ordinal-Sequence of W by A183, A184, FUNCT_2:def 1, RELSET_1:4;
let H be ZF-formula; :: thesis: ( H is atomic implies S1[H] )
assume A185: ( H is being_equality or H is being_membership ) ; :: according to ZF_LANG:def 15 :: thesis: S1[H]
take phi ; :: thesis: ( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

thus A186: phi is increasing :: thesis: ( phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )
proof
let A be Ordinal; :: according to ORDINAL2:def 12 :: thesis: for b1 being set holds
( not A in b1 or not b1 in dom phi or phi . A in phi . b1 )

let B be Ordinal; :: thesis: ( not A in B or not B in dom phi or phi . A in phi . B )
assume A187: ( A in B & B in dom phi ) ; :: thesis: phi . A in phi . B
then phi . A = A by FUNCT_1:18, ORDINAL1:10;
hence phi . A in phi . B by A187, FUNCT_1:18; :: thesis: verum
end;
thus phi is continuous :: thesis: for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )
proof
let A be Ordinal; :: according to ORDINAL2:def 13 :: thesis: for b1 being set holds
( not A in dom phi or A = 0 or not A is limit_ordinal or not b1 = phi . A or b1 is_limes_of phi | A )

let B be Ordinal; :: thesis: ( not A in dom phi or A = 0 or not A is limit_ordinal or not B = phi . A or B is_limes_of phi | A )
assume that
A188: A in dom phi and
A189: ( A <> 0 & A is limit_ordinal ) and
A190: B = phi . A ; :: thesis: B is_limes_of phi | A
A191: A c= dom phi by A188, ORDINAL1:def 2;
phi | A = phi * (id A) by RELAT_1:65
.= id ((dom phi) /\ A) by FUNCT_1:22
.= id A by A191, XBOOLE_1:28 ;
then A192: rng (phi | A) = A ;
phi . A = A by A188, FUNCT_1:18;
then A193: sup (phi | A) = B by A190, A192, ORDINAL2:18;
A194: phi | A is increasing by A186, ORDINAL4:15;
dom (phi | A) = A by A191, RELAT_1:62;
hence B is_limes_of phi | A by A189, A193, A194, ORDINAL4:8; :: thesis: verum
end;
let a be Ordinal of W; :: thesis: ( phi . a = a & {} <> a implies for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) )

assume that
phi . a = a and
{} <> a ; :: thesis: for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let f be Function of VAR,(L . a); :: thesis: ( Union L,(Union L) ! f |= H iff L . a,f |= H )
thus ( Union L,(Union L) ! f |= H implies L . a,f |= H ) :: thesis: ( L . a,f |= H implies Union L,(Union L) ! f |= H )
proof
assume A195: Union L,(Union L) ! f |= H ; :: thesis: L . a,f |= H
A196: (Union L) ! f = f by Th16, ZF_LANG1:def 1;
A197: now :: thesis: ( H is being_membership implies L . a,f |= H )end;
now :: thesis: ( H is being_equality implies L . a,f |= H )end;
hence L . a,f |= H by A185, A197; :: thesis: verum
end;
assume A200: L . a,f |= H ; :: thesis: Union L,(Union L) ! f |= H
A201: (Union L) ! f = f by Th16, ZF_LANG1:def 1;
A202: now :: thesis: ( H is being_membership implies Union L,(Union L) ! f |= H )end;
now :: thesis: ( H is being_equality implies Union L,(Union L) ! f |= H )end;
hence Union L,(Union L) ! f |= H by A185, A202; :: thesis: verum
end;
A205: for H being ZF-formula st H is negative & S1[ the_argument_of H] holds
S1[H]
proof
let H be ZF-formula; :: thesis: ( H is negative & S1[ the_argument_of H] implies S1[H] )
assume H is negative ; :: thesis: ( not S1[ the_argument_of H] or S1[H] )
then A206: H = 'not' (the_argument_of H) by ZF_LANG:def 30;
given phi being Ordinal-Sequence of W such that A207: ( phi is increasing & phi is continuous ) and
A208: for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= the_argument_of H iff L . a,f |= the_argument_of H ) ; :: thesis: S1[H]
take phi ; :: thesis: ( phi is increasing & phi is continuous & ( for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) ) )

thus ( phi is increasing & phi is continuous ) by A207; :: thesis: for a being Ordinal of W st phi . a = a & {} <> a holds
for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let a be Ordinal of W; :: thesis: ( phi . a = a & {} <> a implies for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H ) )

assume A209: ( phi . a = a & {} <> a ) ; :: thesis: for f being Function of VAR,(L . a) holds
( Union L,(Union L) ! f |= H iff L . a,f |= H )

let f be Function of VAR,(L . a); :: thesis: ( Union L,(Union L) ! f |= H iff L . a,f |= H )
thus ( Union L,(Union L) ! f |= H implies L . a,f |= H ) :: thesis: ( L . a,f |= H implies Union L,(Union L) ! f |= H )
proof end;
assume L . a,f |= H ; :: thesis: Union L,(Union L) ! f |= H
then not L . a,f |= the_argument_of H by A206, ZF_MODEL:14;
then not Union L,(Union L) ! f |= the_argument_of H by A208, A209;
hence Union L,(Union L) ! f |= H by A206, ZF_MODEL:14; :: thesis: verum
end;
thus for H being ZF-formula holds S1[H] from ZF_LANG:sch 1(A182, A205, A161, A6); :: thesis: verum