Metamath Proof Explorer

Theorem pm3.22

Description: Theorem *3.22 of WhiteheadRussell p. 111. (Contributed by NM, 3-Jan-2005) (Proof shortened by Wolf Lammen, 13-Nov-2012)

Ref Expression
Assertion pm3.22 
|- ( ( ph /\ ps ) -> ( ps /\ ph ) )

Proof

Step Hyp Ref Expression
1 id 
 |-  ( ( ps /\ ph ) -> ( ps /\ ph ) )
2 1 ancoms 
 |-  ( ( ph /\ ps ) -> ( ps /\ ph ) )