Metamath Proof Explorer


Theorem pm2.24d

Description: Deduction form of pm2.24 . (Contributed by NM, 30-Jan-2006)

Ref Expression
Hypothesis pm2.24d.1 ( 𝜑𝜓 )
Assertion pm2.24d ( 𝜑 → ( ¬ 𝜓𝜒 ) )

Proof

Step Hyp Ref Expression
1 pm2.24d.1 ( 𝜑𝜓 )
2 1 a1d ( 𝜑 → ( ¬ 𝜒𝜓 ) )
3 2 con1d ( 𝜑 → ( ¬ 𝜓𝜒 ) )