Metamath Proof Explorer


Theorem bnj1520

Description: Technical lemma for bnj1500 . 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 bnj1520.1
|- B = { d | ( d C_ A /\ A. x e. d _pred ( x , A , R ) C_ d ) }
bnj1520.2
|- Y = <. x , ( f |` _pred ( x , A , R ) ) >.
bnj1520.3
|- C = { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) }
bnj1520.4
|- F = U. C
Assertion bnj1520
|- ( ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. ) -> A. f ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. ) )

Proof

Step Hyp Ref Expression
1 bnj1520.1
 |-  B = { d | ( d C_ A /\ A. x e. d _pred ( x , A , R ) C_ d ) }
2 bnj1520.2
 |-  Y = <. x , ( f |` _pred ( x , A , R ) ) >.
3 bnj1520.3
 |-  C = { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) }
4 bnj1520.4
 |-  F = U. C
5 3 bnj1317
 |-  ( w e. C -> A. f w e. C )
6 5 nfcii
 |-  F/_ f C
7 6 nfuni
 |-  F/_ f U. C
8 4 7 nfcxfr
 |-  F/_ f F
9 nfcv
 |-  F/_ f x
10 8 9 nffv
 |-  F/_ f ( F ` x )
11 nfcv
 |-  F/_ f G
12 nfcv
 |-  F/_ f _pred ( x , A , R )
13 8 12 nfres
 |-  F/_ f ( F |` _pred ( x , A , R ) )
14 9 13 nfop
 |-  F/_ f <. x , ( F |` _pred ( x , A , R ) ) >.
15 11 14 nffv
 |-  F/_ f ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. )
16 10 15 nfeq
 |-  F/ f ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. )
17 16 nf5ri
 |-  ( ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. ) -> A. f ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. ) )