Theorem truortru 1340

Description: A \/ identity. (Contributed by Anthony Hart, 22-Oct-2010.) (Proof shortened by Andrew Salmon, 13-May-2011.)

Assertion

Ref	Expression
truortru	|- (( T. \/ T. ) <-> T. )

Proof of Theorem truortru

Step	Hyp	Ref	Expression
1		oridm 500	1 |- (( T. \/ T. ) <-> T. )

Syntax hints:   <-> wb 176   \/ wo 357   T. wtru 1316

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 177  df-or 359

This theorem is referenced by: (None)