Theorem nfnfc1 2311

Description: x is bound in F/_ x A. (Contributed by Mario Carneiro, 11-Aug-2016.)

Assertion

Ref	Expression
nfnfc1	|- F/ x F/_ x A

Proof of Theorem nfnfc1

Dummy variable y is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-nfc 2297	. 2 |- ( F/_ x A <-> A. y F/ x y e. A )
2		nfnf1 1532	. . 3 |- F/ x F/ x y e. A
3	2	nfal 1564	. 2 |- F/ x A. y F/ x y e. A
4	1, 3	nfxfr 1462	1 |- F/ x F/_ x A

Syntax hints:   A.wal 1341   F/wnf 1448   e. wcel 2136   F/_wnfc 2295

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ial 1522

This theorem depends on definitions:  df-bi 116  df-nf 1449  df-nfc 2297

This theorem is referenced by:  vtoclgft  2776  sbcralt  3027  sbcrext  3028  csbiebt  3084  nfopd  3775  nfimad  4955  nffvd  5498