Metamath Proof Explorer


Theorem jaoi

Description: Inference disjoining the antecedents of two implications. (Contributed by NM, 5-Apr-1994)

Ref Expression
Hypotheses jaoi.1 ( 𝜑𝜓 )
jaoi.2 ( 𝜒𝜓 )
Assertion jaoi ( ( 𝜑𝜒 ) → 𝜓 )

Proof

Step Hyp Ref Expression
1 jaoi.1 ( 𝜑𝜓 )
2 jaoi.2 ( 𝜒𝜓 )
3 pm2.53 ( ( 𝜑𝜒 ) → ( ¬ 𝜑𝜒 ) )
4 3 2 syl6 ( ( 𝜑𝜒 ) → ( ¬ 𝜑𝜓 ) )
5 4 1 pm2.61d2 ( ( 𝜑𝜒 ) → 𝜓 )