Description: A \/ identity. (Contributed by Anthony Hart, 22-Oct-2010)
Ref | Expression | ||
---|---|---|---|
Assertion | truorfal | |- ( ( T. \/ F. ) <-> T. ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | tru | |- T. |
|
2 | 1 | orci | |- ( T. \/ F. ) |
3 | 2 | bitru | |- ( ( T. \/ F. ) <-> T. ) |