MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  pm4.67 Unicode version

Theorem pm4.67 419
Description: Theorem *4.67 of [WhiteheadRussell] p. 120. (Contributed by NM, 3-Jan-2005.)
Assertion
Ref Expression
pm4.67  |-  ( -.  ( -.  ph  ->  -. 
ps )  <->  ( -.  ph 
/\  ps ) )

Proof of Theorem pm4.67
StepHypRef Expression
1 pm4.63 412 1  |-  ( -.  ( -.  ph  ->  -. 
ps )  <->  ( -.  ph 
/\  ps ) )
Colors of variables: wff set class
Syntax hints:   -. wn 5    -> wi 6    <-> wb 178    /\ wa 360
This theorem was proved from axioms:  ax-1 7  ax-2 8  ax-3 9  ax-mp 10
This theorem depends on definitions:  df-bi 179  df-an 362
  Copyright terms: Public domain W3C validator