Metamath Proof Explorer


Theorem pm2.86d

Description: Deduction associated with pm2.86 . (Contributed by NM, 29-Jun-1995) (Proof shortened by Wolf Lammen, 3-Apr-2013)

Ref Expression
Hypothesis pm2.86d.1 ( 𝜑 → ( ( 𝜓𝜒 ) → ( 𝜓𝜃 ) ) )
Assertion pm2.86d ( 𝜑 → ( 𝜓 → ( 𝜒𝜃 ) ) )

Proof

Step Hyp Ref Expression
1 pm2.86d.1 ( 𝜑 → ( ( 𝜓𝜒 ) → ( 𝜓𝜃 ) ) )
2 ax-1 ( 𝜒 → ( 𝜓𝜒 ) )
3 2 1 syl5 ( 𝜑 → ( 𝜒 → ( 𝜓𝜃 ) ) )
4 3 com23 ( 𝜑 → ( 𝜓 → ( 𝜒𝜃 ) ) )