Metamath Proof Explorer

Theorem truortru

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

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

Proof

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