Metamath Proof Explorer


Theorem com4l

Description: Commutation of antecedents. Rotate left. (Contributed by NM, 25-Apr-1994) (Proof shortened by Mel L. O'Cat, 15-Aug-2004)

Ref Expression
Hypothesis com4.1 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )
Assertion com4l ( 𝜓 → ( 𝜒 → ( 𝜃 → ( 𝜑𝜏 ) ) ) )

Proof

Step Hyp Ref Expression
1 com4.1 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )
2 1 com3l ( 𝜓 → ( 𝜒 → ( 𝜑 → ( 𝜃𝜏 ) ) ) )
3 2 com34 ( 𝜓 → ( 𝜒 → ( 𝜃 → ( 𝜑𝜏 ) ) ) )