Metamath Proof Explorer


Theorem pm4.71d

Description: Deduction converting an implication to a biconditional with conjunction. Deduction from Theorem *4.71 of WhiteheadRussell p. 120. (Contributed by Mario Carneiro, 25-Dec-2016)

Ref Expression
Hypothesis pm4.71rd.1
|- ( ph -> ( ps -> ch ) )
Assertion pm4.71d
|- ( ph -> ( ps <-> ( ps /\ ch ) ) )

Proof

Step Hyp Ref Expression
1 pm4.71rd.1
 |-  ( ph -> ( ps -> ch ) )
2 pm4.71
 |-  ( ( ps -> ch ) <-> ( ps <-> ( ps /\ ch ) ) )
3 1 2 sylib
 |-  ( ph -> ( ps <-> ( ps /\ ch ) ) )