Theorem tsna2 36230

Description: A Tseitin axiom for logical incompatibility, in deduction form. (Contributed by Giovanni Mascellani, 24-Mar-2018.)

Assertion

Ref	Expression
tsna2	⊢ (𝜃 → (𝜑 ∨ (𝜑 ⊼ 𝜓)))

Proof of Theorem tsna2

Step	Hyp	Ref	Expression
1		tsan2 36227	. 2 ⊢ (𝜃 → (𝜑 ∨ ¬ (𝜑 ∧ 𝜓)))
2		df-nan 1484	. . 3 ⊢ ((𝜑 ⊼ 𝜓) ↔ ¬ (𝜑 ∧ 𝜓))
3	2	orbi2i 909	. 2 ⊢ ((𝜑 ∨ (𝜑 ⊼ 𝜓)) ↔ (𝜑 ∨ ¬ (𝜑 ∧ 𝜓)))
4	1, 3	sylibr 233	1 ⊢ (𝜃 → (𝜑 ∨ (𝜑 ⊼ 𝜓)))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 395   ∨ wo 843   ⊼ wnan 1483

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

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-nan 1484

This theorem is referenced by: (None)