Metamath Proof Explorer


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 φ

Proof

Step Hyp Ref Expression
1 falim φ