Metamath Proof Explorer


Theorem bnj1491

Description: Technical lemma for bnj60 . This lemma may no longer be used or have become an indirect lemma of the theorem in question (i.e. a lemma of a lemma... of the theorem). (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Hypotheses bnj1491.1
|- B = { d | ( d C_ A /\ A. x e. d _pred ( x , A , R ) C_ d ) }
bnj1491.2
|- Y = <. x , ( f |` _pred ( x , A , R ) ) >.
bnj1491.3
|- C = { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) }
bnj1491.4
|- ( ta <-> ( f e. C /\ dom f = ( { x } u. _trCl ( x , A , R ) ) ) )
bnj1491.5
|- D = { x e. A | -. E. f ta }
bnj1491.6
|- ( ps <-> ( R _FrSe A /\ D =/= (/) ) )
bnj1491.7
|- ( ch <-> ( ps /\ x e. D /\ A. y e. D -. y R x ) )
bnj1491.8
|- ( ta' <-> [. y / x ]. ta )
bnj1491.9
|- H = { f | E. y e. _pred ( x , A , R ) ta' }
bnj1491.10
|- P = U. H
bnj1491.11
|- Z = <. x , ( P |` _pred ( x , A , R ) ) >.
bnj1491.12
|- Q = ( P u. { <. x , ( G ` Z ) >. } )
bnj1491.13
|- ( ch -> ( Q e. C /\ dom Q = ( { x } u. _trCl ( x , A , R ) ) ) )
Assertion bnj1491
|- ( ( ch /\ Q e. _V ) -> E. f ( f e. C /\ dom f = ( { x } u. _trCl ( x , A , R ) ) ) )

Proof

Step Hyp Ref Expression
1 bnj1491.1
 |-  B = { d | ( d C_ A /\ A. x e. d _pred ( x , A , R ) C_ d ) }
2 bnj1491.2
 |-  Y = <. x , ( f |` _pred ( x , A , R ) ) >.
3 bnj1491.3
 |-  C = { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) }
4 bnj1491.4
 |-  ( ta <-> ( f e. C /\ dom f = ( { x } u. _trCl ( x , A , R ) ) ) )
5 bnj1491.5
 |-  D = { x e. A | -. E. f ta }
6 bnj1491.6
 |-  ( ps <-> ( R _FrSe A /\ D =/= (/) ) )
7 bnj1491.7
 |-  ( ch <-> ( ps /\ x e. D /\ A. y e. D -. y R x ) )
8 bnj1491.8
 |-  ( ta' <-> [. y / x ]. ta )
9 bnj1491.9
 |-  H = { f | E. y e. _pred ( x , A , R ) ta' }
10 bnj1491.10
 |-  P = U. H
11 bnj1491.11
 |-  Z = <. x , ( P |` _pred ( x , A , R ) ) >.
12 bnj1491.12
 |-  Q = ( P u. { <. x , ( G ` Z ) >. } )
13 bnj1491.13
 |-  ( ch -> ( Q e. C /\ dom Q = ( { x } u. _trCl ( x , A , R ) ) ) )
14 1 2 3 4 5 6 7 8 9 10 11 12 bnj1466
 |-  ( w e. Q -> A. f w e. Q )
15 14 nfcii
 |-  F/_ f Q
16 3 bnj1317
 |-  ( w e. C -> A. f w e. C )
17 16 nfcii
 |-  F/_ f C
18 15 17 nfel
 |-  F/ f Q e. C
19 15 nfdm
 |-  F/_ f dom Q
20 19 nfeq1
 |-  F/ f dom Q = ( { x } u. _trCl ( x , A , R ) )
21 18 20 nfan
 |-  F/ f ( Q e. C /\ dom Q = ( { x } u. _trCl ( x , A , R ) ) )
22 eleq1
 |-  ( f = Q -> ( f e. C <-> Q e. C ) )
23 dmeq
 |-  ( f = Q -> dom f = dom Q )
24 23 eqeq1d
 |-  ( f = Q -> ( dom f = ( { x } u. _trCl ( x , A , R ) ) <-> dom Q = ( { x } u. _trCl ( x , A , R ) ) ) )
25 22 24 anbi12d
 |-  ( f = Q -> ( ( f e. C /\ dom f = ( { x } u. _trCl ( x , A , R ) ) ) <-> ( Q e. C /\ dom Q = ( { x } u. _trCl ( x , A , R ) ) ) ) )
26 15 21 25 spcegf
 |-  ( Q e. _V -> ( ( Q e. C /\ dom Q = ( { x } u. _trCl ( x , A , R ) ) ) -> E. f ( f e. C /\ dom f = ( { x } u. _trCl ( x , A , R ) ) ) ) )
27 13 26 mpan9
 |-  ( ( ch /\ Q e. _V ) -> E. f ( f e. C /\ dom f = ( { x } u. _trCl ( x , A , R ) ) ) )