Description: Standard propositional axiom derived from Lukasiewicz axioms. (Contributed by NM, 22-Dec-2002) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | ax1 | ⊢ ( 𝜑 → ( 𝜓 → 𝜑 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | luklem5 | ⊢ ( 𝜑 → ( 𝜓 → 𝜑 ) ) |