Metamath Proof Explorer


Theorem 3impd

Description: Importation deduction for triple conjunction. (Contributed by NM, 26-Oct-2006)

Ref Expression
Hypothesis 3imp1.1 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )
Assertion 3impd ( 𝜑 → ( ( 𝜓𝜒𝜃 ) → 𝜏 ) )

Proof

Step Hyp Ref Expression
1 3imp1.1 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )
2 1 com4l ( 𝜓 → ( 𝜒 → ( 𝜃 → ( 𝜑𝜏 ) ) ) )
3 2 3imp ( ( 𝜓𝜒𝜃 ) → ( 𝜑𝜏 ) )
4 3 com12 ( 𝜑 → ( ( 𝜓𝜒𝜃 ) → 𝜏 ) )