Theorem chvarv 1930

Description: Implicit substitution of y for x into a theorem. (Contributed by NM, 20-Apr-1994.)

Hypotheses

Ref	Expression
chv.1	|- ( x = y -> ( ph <-> ps ) )
chv.2	|- ph

Assertion

Ref	Expression
chvarv	|- ps

Distinct variable group:   ps, x

Allowed substitution hints:   ph( x, y)   ps( y)

Proof of Theorem chvarv

Step	Hyp	Ref	Expression
1		chv.1	. . 3 |- ( x = y -> ( ph <-> ps ) )
2	1	spv 1853	. 2 |- ( A. x ph -> ps )
3		chv.2	. 2 |- ph
4	2, 3	mpg 1444	1 |- ps

Syntax hints:   -> wi 4   <-> wb 104

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 1440  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527

This theorem depends on definitions:  df-bi 116  df-nf 1454

This theorem is referenced by:  axext3  2153  axsep2  4108  tz6.12f  5525  ltordlem  8401  bdsep2  13921  strcoll2  14018