Metamath Proof Explorer


Theorem exp520

Description: A triple exportation inference. (Contributed by Jeff Hankins, 8-Jul-2009)

Ref Expression
Hypothesis exp520.1 ( ( ( 𝜑𝜓𝜒 ) ∧ ( 𝜃𝜏 ) ) → 𝜂 )
Assertion exp520 ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃 → ( 𝜏𝜂 ) ) ) ) )

Proof

Step Hyp Ref Expression
1 exp520.1 ( ( ( 𝜑𝜓𝜒 ) ∧ ( 𝜃𝜏 ) ) → 𝜂 )
2 1 ex ( ( 𝜑𝜓𝜒 ) → ( ( 𝜃𝜏 ) → 𝜂 ) )
3 2 exp5o ( 𝜑 → ( 𝜓 → ( 𝜒 → ( 𝜃 → ( 𝜏𝜂 ) ) ) ) )