Theorem truortru 1585

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

Assertion

Ref	Expression
truortru	⊢ ((⊤ ∨ ⊤) ↔ ⊤)

Proof of Theorem truortru

Step	Hyp	Ref	Expression
1		oridm 911	1 ⊢ ((⊤ ∨ ⊤) ↔ ⊤)

Syntax hints:   ↔ wb 208   ∨ wo 854  ⊤wtru 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 855

This theorem is referenced by:  trunortru  1597