Theorem re1luk1 1475

Description: luk-1 1420 derived from the Tarski-Bernays-Wajsberg axioms. (Contributed by Anthony Hart, 16-Aug-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
re1luk1	⊢ ((φ → ψ) → ((ψ → χ) → (φ → χ)))

Proof of Theorem re1luk1

Step	Hyp	Ref	Expression
1		tbw-ax1 1465	1 ⊢ ((φ → ψ) → ((ψ → χ) → (φ → χ)))

This proof depends on syntax axioms:   → wi 4

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7

This theorem is used by: (None)