Theorem falimfal 1347

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

Assertion

Ref	Expression
falimfal	⊢ (( ⊥ → ⊥ ) ↔ ⊤ )

Proof of Theorem falimfal

Step	Hyp	Ref	Expression
1		id 19	. 2 ⊢ ( ⊥ → ⊥ )
2	1	bitru 1326	1 ⊢ (( ⊥ → ⊥ ) ↔ ⊤ )

Syntax hints:   → wi 4   ↔ wb 176   ⊤ wtru 1316   ⊥ wfal 1317

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 177  df-tru 1319

This theorem is referenced by: (None)