Theorem pm11.53 1888

Description: Theorem *11.53 in [WhiteheadRussell] p. 164. (Contributed by Andrew Salmon, 24-May-2011.)

Assertion

Ref	Expression
pm11.53	|- ( A. x A. y ( ph -> ps ) <-> ( E. x ph -> A. y ps ) )

Distinct variable groups:   ph, y   ps, x

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

Proof of Theorem pm11.53

Step	Hyp	Ref	Expression
1		19.21v 1866	. . 3 |- ( A. y ( ph -> ps ) <-> ( ph -> A. y ps ) )
2	1	albii 1463	. 2 |- ( A. x A. y ( ph -> ps ) <-> A. x ( ph -> A. y ps ) )
3		ax-17 1519	. . . 4 |- ( ps -> A. x ps )
4	3	hbal 1470	. . 3 |- ( A. y ps -> A. x A. y ps )
5	4	19.23h 1491	. 2 |- ( A. x ( ph -> A. y ps ) <-> ( E. x ph -> A. y ps ) )
6	2, 5	bitri 183	1 |- ( A. x A. y ( ph -> ps ) <-> ( E. x ph -> A. y ps ) )

Syntax hints:   -> wi 4   <-> wb 104   A.wal 1346   E.wex 1485

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-7 1441  ax-gen 1442  ax-ie2 1487  ax-4 1503  ax-17 1519  ax-ial 1527  ax-i5r 1528

This theorem depends on definitions:  df-bi 116

This theorem is referenced by: (None)