Metamath Proof Explorer


Theorem exp44

Description: An exportation inference. (Contributed by NM, 26-Apr-1994)

Ref Expression
Hypothesis exp44.1 ( ( 𝜑 ∧ ( ( 𝜓𝜒 ) ∧ 𝜃 ) ) → 𝜏 )
Assertion exp44 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )

Proof

Step Hyp Ref Expression
1 exp44.1 ( ( 𝜑 ∧ ( ( 𝜓𝜒 ) ∧ 𝜃 ) ) → 𝜏 )
2 1 exp32 ( 𝜑 → ( ( 𝜓𝜒 ) → ( 𝜃𝜏 ) ) )
3 2 expd ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )