Metamath Proof Explorer


Theorem ancomsd

Description: Deduction commuting conjunction in antecedent. (Contributed by NM, 12-Dec-2004)

Ref Expression
Hypothesis ancomsd.1 ( 𝜑 → ( ( 𝜓𝜒 ) → 𝜃 ) )
Assertion ancomsd ( 𝜑 → ( ( 𝜒𝜓 ) → 𝜃 ) )

Proof

Step Hyp Ref Expression
1 ancomsd.1 ( 𝜑 → ( ( 𝜓𝜒 ) → 𝜃 ) )
2 1 expcomd ( 𝜑 → ( 𝜒 → ( 𝜓𝜃 ) ) )
3 2 impd ( 𝜑 → ( ( 𝜒𝜓 ) → 𝜃 ) )