Metamath Proof Explorer


Theorem e31an

Description: A virtual deduction elimination rule. (Contributed by Alan Sare, 24-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses e31an.1 (    𝜑    ,    𝜓    ,    𝜒    ▶    𝜃    )
e31an.2 (    𝜑    ▶    𝜏    )
e31an.3 ( ( 𝜃𝜏 ) → 𝜂 )
Assertion e31an (    𝜑    ,    𝜓    ,    𝜒    ▶    𝜂    )

Proof

Step Hyp Ref Expression
1 e31an.1 (    𝜑    ,    𝜓    ,    𝜒    ▶    𝜃    )
2 e31an.2 (    𝜑    ▶    𝜏    )
3 e31an.3 ( ( 𝜃𝜏 ) → 𝜂 )
4 3 ex ( 𝜃 → ( 𝜏𝜂 ) )
5 1 2 4 e31 (    𝜑    ,    𝜓    ,    𝜒    ▶    𝜂    )