Theorem nfth 1393

Description: No variable is (effectively) free in a theorem. (Contributed by Mario Carneiro, 11-Aug-2016.)

Hypothesis

Ref	Expression
hbth.1	|- ph

Assertion

Ref	Expression
nfth	|- F/ x ph

Proof of Theorem nfth

Step	Hyp	Ref	Expression
1		hbth.1	. . 3 |- ph
2	1	hbth 1392	. 2 |- ( ph -> A. x ph )
3	2	nfi 1391	1 |- F/ x ph

Syntax hints:   F/wnf 1389

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-gen 1378

This theorem depends on definitions:  df-bi 115  df-nf 1390

This theorem is referenced by:  nftru  1395  nfequid  1630  sbt  1707  sbc2ie  2885