Metamath Proof Explorer


Theorem exp42

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

Ref Expression
Hypothesis exp42.1 ( ( ( 𝜑 ∧ ( 𝜓𝜒 ) ) ∧ 𝜃 ) → 𝜏 )
Assertion exp42 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )

Proof

Step Hyp Ref Expression
1 exp42.1 ( ( ( 𝜑 ∧ ( 𝜓𝜒 ) ) ∧ 𝜃 ) → 𝜏 )
2 1 exp31 ( 𝜑 → ( ( 𝜓𝜒 ) → ( 𝜃𝜏 ) ) )
3 2 expd ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃𝜏 ) ) ) )