Metamath Proof Explorer

Theorem pm3.3

Description: Theorem *3.3 (Exp) of WhiteheadRussell p. 112. (Contributed by NM, 3-Jan-2005) (Proof shortened by Wolf Lammen, 24-Mar-2013)

Ref Expression
Assertion pm3.3 
|- ( ( ( ph /\ ps ) -> ch ) -> ( ph -> ( ps -> ch ) ) )

Proof

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