Theorem pm2.521g 175

Description: A general instance of Theorem *2.521 of [WhiteheadRussell] p. 107. (Contributed by BJ, 28-Oct-2023.)

Assertion

Ref	Expression
pm2.521g	⊢ (¬ (𝜑 → 𝜓) → (𝜓 → 𝜒))

Proof of Theorem pm2.521g

Step	Hyp	Ref	Expression
1		conax1 171	. 2 ⊢ (¬ (𝜑 → 𝜓) → ¬ 𝜓)
2	1	pm2.21d 122	1 ⊢ (¬ (𝜑 → 𝜓) → (𝜓 → 𝜒))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem is used by:  pm2.521  177  pm5.14  960  rp-fakeimass  44266