NFE Home New Foundations Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  NFE Home  >  Th. List  >  modal-b Unicode version

Theorem modal-b 1752
Description: The analog in our "pure" predicate calculus of the Brouwer axiom (B) of modal logic S5. (Contributed by NM, 5-Oct-2005.)
Assertion
Ref Expression
modal-b

Proof of Theorem modal-b
StepHypRef Expression
1 ax6o 1750 . 2
21con4i 122 1
Colors of variables: wff setvar class
Syntax hints:   wn 3   wi 4  wal 1540
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-11 1746
This theorem depends on definitions:  df-bi 177  df-ex 1542
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator