Theorem pm2.5 169

Description: Theorem *2.5 of [WhiteheadRussell] p. 107. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm2.5	⊢ (¬ (𝜑 → 𝜓) → (¬ 𝜑 → 𝜓))

Proof of Theorem pm2.5

Step	Hyp	Ref	Expression
1		pm2.5g 168	1 ⊢ (¬ (𝜑 → 𝜓) → (¬ 𝜑 → 𝜓))

Syntax hints:  ¬ wn 3   → wi 4

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem is referenced by: (None)