Theorem tb-ax3 14130

Description: The third of three axioms in the Tarski-Bernays axiom system.

This axiom, along with ax-mp 7, tb-ax1 14128, and tb-ax2 14129, can be used to derive any theorem or rule that uses only ->.

Assertion

Ref	Expression
tb-ax3	|- (((ph -> ps) -> ph) -> ph)

Proof of Theorem tb-ax3

Step	Hyp	Ref	Expression
1		peirce 98	1 |- (((ph -> ps) -> ph) -> ph)

Syntax hints:   -> wi 3

This theorem is referenced by:  re1ax2lem 14132  re1ax2 14133

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7

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