Metamath Proof Explorer

Theorem pm3.21

Description: Join antecedents with conjunction. Theorem *3.21 of WhiteheadRussell p. 111. (Contributed by NM, 5-Aug-1993)

Ref Expression
Assertion pm3.21 
|- ( ph -> ( ps -> ( ps /\ ph ) ) )

Proof

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