Theorem pm2.46 690

Description: Theorem *2.46 of [WhiteheadRussell] p. 106. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm2.46	⊢ (¬ (𝜑 ∨ 𝜓) → ¬ 𝜓)

Proof of Theorem pm2.46

Step	Hyp	Ref	Expression
1		olc 664	. 2 ⊢ (𝜓 → (𝜑 ∨ 𝜓))
2	1	con3i 594	1 ⊢ (¬ (𝜑 ∨ 𝜓) → ¬ 𝜓)

Syntax hints:  ¬ wn 3   → wi 4   ∨ wo 661

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-in1 576  ax-in2 577  ax-io 662

This theorem depends on definitions:  df-bi 115

This theorem is referenced by:  pm2.48  692  pm2.49  693  ioran  701  eueq3dc  2766  regexmidlem1  4276