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Metamath Proof Explorer


Theorem anc2l

Description: Conjoin antecedent to left of consequent in nested implication. (Contributed by NM, 10-Aug-1994) (Proof shortened by Wolf Lammen, 14-Jul-2013)

Ref Expression
Assertion anc2l ( ( 𝜑 → ( 𝜓𝜒 ) ) → ( 𝜑 → ( 𝜓 → ( 𝜑𝜒 ) ) ) )

Proof

Step Hyp Ref Expression
1 pm5.42 ( ( 𝜑 → ( 𝜓𝜒 ) ) ↔ ( 𝜑 → ( 𝜓 → ( 𝜑𝜒 ) ) ) )
2 1 biimpi ( ( 𝜑 → ( 𝜓𝜒 ) ) → ( 𝜑 → ( 𝜓 → ( 𝜑𝜒 ) ) ) )