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

Theorem impbida 805
Description: Deduce an equivalence from two implications. (Contributed by NM, 17-Feb-2007.)
Hypotheses
Ref Expression
impbida.1
impbida.2
Assertion
Ref Expression
impbida

Proof of Theorem impbida
StepHypRef Expression
1 impbida.1 . . 3
21ex 423 . 2
3 impbida.2 . . 3
43ex 423 . 2
52, 4impbid 183 1
Colors of variables: wff setvar class
Syntax hints:   wi 4   wb 176   wa 358
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-an 360
This theorem is referenced by:  eqrdav  2352  funfvbrb  5401  f1o2d  5727  ersymb  5953  erth  5968
  Copyright terms: Public domain W3C validator