Metamath Proof Explorer

Theorem falxortru

Description: A \/_ identity. (Contributed by David A. Wheeler, 9-May-2015) (Proof shortened by Wolf Lammen, 10-Jul-2020)

Ref Expression
Assertion falxortru 
|- ( ( F. \/_ T. ) <-> T. )

Proof

Step Hyp Ref Expression
1 xorcom 
 |-  ( ( F. \/_ T. ) <-> ( T. \/_ F. ) )
2 truxorfal 
 |-  ( ( T. \/_ F. ) <-> T. )
3 1 2 bitri 
 |-  ( ( F. \/_ T. ) <-> T. )