Theorem tsxo4 38147

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

Assertion

Ref	Expression
tsxo4	⊢ (𝜃 → ((¬ 𝜑 ∨ 𝜓) ∨ (𝜑 ⊻ 𝜓)))

Proof of Theorem tsxo4

Step	Hyp	Ref	Expression
1		tsbi4 38143	. 2 ⊢ (𝜃 → ((¬ 𝜑 ∨ 𝜓) ∨ ¬ (𝜑 ↔ 𝜓)))
2		df-xor 1512	. . . 4 ⊢ ((𝜑 ⊻ 𝜓) ↔ ¬ (𝜑 ↔ 𝜓))
3	2	bicomi 224	. . 3 ⊢ (¬ (𝜑 ↔ 𝜓) ↔ (𝜑 ⊻ 𝜓))
4	3	orbi2i 913	. 2 ⊢ (((¬ 𝜑 ∨ 𝜓) ∨ ¬ (𝜑 ↔ 𝜓)) ↔ ((¬ 𝜑 ∨ 𝜓) ∨ (𝜑 ⊻ 𝜓)))
5	1, 4	sylib 218	1 ⊢ (𝜃 → ((¬ 𝜑 ∨ 𝜓) ∨ (𝜑 ⊻ 𝜓)))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 206   ∨ wo 848   ⊻ wxo 1511

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 207  df-or 849  df-xor 1512

This theorem is referenced by: (None)