Metamath Proof Explorer


Theorem com34

Description: Commutation of antecedents. Swap 3rd and 4th. Deduction associated with com23 . Double deduction associated with com12 . (Contributed by NM, 25-Apr-1994)

Ref Expression
Hypothesis com4.1 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )
Assertion com34 ( 𝜑 → ( 𝜓 → ( 𝜃 → ( 𝜒𝜏 ) ) ) )

Proof

Step Hyp Ref Expression
1 com4.1 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )
2 pm2.04 ( ( 𝜒 → ( 𝜃𝜏 ) ) → ( 𝜃 → ( 𝜒𝜏 ) ) )
3 1 2 syl6 ( 𝜑 → ( 𝜓 → ( 𝜃 → ( 𝜒𝜏 ) ) ) )