Theorem ax1 669

Description: Standard propositional axiom derived from Lukasiewicz axioms.

Assertion

Ref	Expression
ax1	⊢ (φ → (ψ → φ))

Proof of Theorem ax1

Step	Hyp	Ref	Expression
1		luklem5 665	1 ⊢ (φ → (ψ → φ))

Syntax hints:   → wi 2

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6

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