Theorem tb-ax1 32378

Description: The first of three axioms in the Tarski-Bernays axiom system. (Contributed by Anthony Hart, 16-Aug-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
tb-ax1	|- ( ( ph -> ps ) -> ( ( ps -> ch ) -> ( ph -> ch ) ) )

Proof of Theorem tb-ax1

Step	Hyp	Ref	Expression
1		imim1 83	1 |- ( ( ph -> ps ) -> ( ( ps -> ch ) -> ( ph -> ch ) ) )

Syntax hints:   -> wi 4

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

This theorem is referenced by:  tbsyl  32381  re1ax2lem  32382  re1ax2  32383