Theorem truorfal 1575

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

Assertion

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

Proof of Theorem truorfal

Step	Hyp	Ref	Expression
1		tru 1541	. . 3 ⊢ ⊤
2	1	orci 861	. 2 ⊢ (⊤ ∨ ⊥)
3	2	bitru 1546	1 ⊢ ((⊤ ∨ ⊥) ↔ ⊤)

Syntax hints:   ↔ wb 208   ∨ wo 843  ⊤wtru 1538  ⊥wfal 1549

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 209  df-or 844  df-tru 1540

This theorem is referenced by:  trunorfal  1588