Theorem chvar 1640

Description: Implicit substitution of y for x into a theorem. (Contributed by Raph Levien, 9-Jul-2003.) (Revised by Mario Carneiro, 3-Oct-2016.)

Hypotheses

Ref	Expression
chvar.1	|- F/ x ps
chvar.2	|- ( x = y -> ( ph <-> ps ) )
chvar.3	|- ph

Assertion

Ref	Expression
chvar	|- ps

Proof of Theorem chvar

Step	Hyp	Ref	Expression
1		chvar.1	. . 3 |- F/ x ps
2		chvar.2	. . . 4 |- ( x = y -> ( ph <-> ps ) )
3	2	biimpd 132	. . 3 |- ( x = y -> ( ph -> ps ) )
4	1, 3	spim 1626	. 2 |- ( A. x ph -> ps )
5		chvar.3	. 2 |- ph
6	4, 5	mpg 1340	1 |- ps

Syntax hints:   -> wi 4   <-> wb 98   F/wnf 1349

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-4 1400  ax-i9 1423  ax-ial 1427

This theorem depends on definitions:  df-bi 110  df-nf 1350

This theorem is referenced by:  csbhypf  2885  opelopabsb  3997  findes  4326  fvmptssdm  5255  dfoprab4f  5819  dom2lem  6252  uzind4s  8533