Metamath Proof Explorer

Theorem pm3.42

Description: Theorem *3.42 of WhiteheadRussell p. 113. (Contributed by NM, 3-Jan-2005)

Ref Expression
Assertion pm3.42 
|- ( ( ps -> ch ) -> ( ( ph /\ ps ) -> ch ) )

Proof

Step Hyp Ref Expression
1 simpr 
 |-  ( ( ph /\ ps ) -> ps )
2 1 imim1i 
 |-  ( ( ps -> ch ) -> ( ( ph /\ ps ) -> ch ) )