Metamath Proof Explorer

Theorem trunantru

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

Ref Expression
Assertion trunantru 
|- ( ( T. -/\ T. ) <-> F. )

Proof

Step Hyp Ref Expression
1 nannot 
 |-  ( -. T. <-> ( T. -/\ T. ) )
2 nottru 
 |-  ( -. T. <-> F. )
3 1 2 bitr3i 
 |-  ( ( T. -/\ T. ) <-> F. )