Description: A Tseitin axiom for logical conjunction, in deduction form. (Contributed by Giovanni Mascellani, 24-Mar-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | tsan1 | ⊢ ( 𝜃 → ( ( ¬ 𝜑 ∨ ¬ 𝜓 ) ∨ ( 𝜑 ∧ 𝜓 ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm3.12 | ⊢ ( ( ¬ 𝜑 ∨ ¬ 𝜓 ) ∨ ( 𝜑 ∧ 𝜓 ) ) | |
2 | 1 | a1i | ⊢ ( 𝜃 → ( ( ¬ 𝜑 ∨ ¬ 𝜓 ) ∨ ( 𝜑 ∧ 𝜓 ) ) ) |