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Metamath Proof Explorer


Theorem biimpcd

Description: Deduce a commuted implication from a logical equivalence. (Contributed by NM, 3-May-1994) (Proof shortened by Wolf Lammen, 22-Sep-2013)

Ref Expression
Hypothesis biimpcd.1
|- ( ph -> ( ps <-> ch ) )
Assertion biimpcd
|- ( ps -> ( ph -> ch ) )

Proof

Step Hyp Ref Expression
1 biimpcd.1
 |-  ( ph -> ( ps <-> ch ) )
2 id
 |-  ( ps -> ps )
3 2 1 syl5ibcom
 |-  ( ps -> ( ph -> ch ) )