pm2.5 - Metamath Proof Explorer

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Theorem pm2.5 171

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 170	1 ⊢ (¬ (𝜑 → 𝜓) → (¬ 𝜑 → 𝜓))

Colors of variables: wff setvar class

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)