Theorem truimfal 1515

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

Assertion

Ref	Expression
truimfal	|- ( ( T. -> F. ) <-> F. )

Proof of Theorem truimfal

Step	Hyp	Ref	Expression
1		trut 1492	. 2 |- ( F. <-> ( T. -> F. ) )
2	1	bicomi 214	1 |- ( ( T. -> F. ) <-> F. )

Syntax hints:   -> wi 4   <-> wb 196   T. wtru 1484   F. wfal 1488

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 197  df-tru 1486

This theorem is referenced by: (None)