Metamath Proof Explorer


Theorem 3expd

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

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

Proof

Step Hyp Ref Expression
1 3expd.1 ( 𝜑 → ( ( 𝜓𝜒𝜃 ) → 𝜏 ) )
2 1 com12 ( ( 𝜓𝜒𝜃 ) → ( 𝜑𝜏 ) )
3 2 3exp ( 𝜓 → ( 𝜒 → ( 𝜃 → ( 𝜑𝜏 ) ) ) )
4 3 com4r ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )