Theorem tbw-ax4

Description: The fourth of four axioms in the Tarski-Bernays-Wajsberg system.

This axiom was added to the Tarski-Bernays axiom system (see tb-ax1 , tb-ax2 , and tb-ax3 ) by Wajsberg for completeness. (Contributed by Anthony Hart, 13-Aug-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	tbw-ax4	$$⊢\perp \to \phi$$

Proof

Step	Hyp	Ref	Expression
1		falim	$$⊢\perp \to \phi$$