Users' Mathboxes Mathbox for Andrew Salmon < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  pm11.7 Unicode version

Theorem pm11.7 27266
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
StepHypRef Expression
1 oridm 501 . 2  |-  ( (
ph  \/  ph )  <->  ph )
212exbii 1590 1  |-  ( E. x E. y (
ph  \/  ph )  <->  E. x E. y ph )
Colors of variables: wff set class
Syntax hints:    <-> wb 177    \/ wo 358   E.wex 1547
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1552  ax-5 1563
This theorem depends on definitions:  df-bi 178  df-or 360  df-ex 1548
  Copyright terms: Public domain W3C validator