Theorem pm11.7 38596

Description: Theorem *11.7 in [WhiteheadRussell] p. 166. (Contributed by Andrew Salmon, 24-May-2011.)

Assertion

Ref	Expression
pm11.7	|- ( E. x E. y ( ph \/ ph ) <-> E. x E. y ph )

Proof of Theorem pm11.7

Step	Hyp	Ref	Expression
1		oridm 536	. 2 |- ( ( ph \/ ph ) <-> ph )
2	1	2exbii 1775	1 |- ( E. x E. y ( ph \/ ph ) <-> E. x E. y ph )

Syntax hints:   <-> wb 196   \/ wo 383   E.wex 1704

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737

This theorem depends on definitions:  df-bi 197  df-or 385  df-ex 1705

This theorem is referenced by: (None)