Theorem truorfal 1341

Description: A ∨ identity. (Contributed by Anthony Hart, 22-Oct-2010.)

Assertion

Ref	Expression
truorfal	⊢ (( ⊤ ∨ ⊥ ) ↔ ⊤ )

Proof of Theorem truorfal

Step	Hyp	Ref	Expression
1		tru 1321	. . 3 ⊢ ⊤
2	1	orci 379	. 2 ⊢ ( ⊤ ∨ ⊥ )
3	2	bitru 1326	1 ⊢ (( ⊤ ∨ ⊥ ) ↔ ⊤ )

This proof depends on syntax axioms:   ↔ wb 176   ∨ wo 357   ⊤ wtru 1316   ⊥ wfal 1317

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This proof depends on definitions:  df-bi 177  df-or 359  df-tru 1319

This theorem is used by: (None)