NFE Home New Foundations Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  NFE Home  >  Th. List  >  syl7bi Unicode version

Theorem syl7bi 221
Description: A mixed syllogism inference from a doubly nested implication and a biconditional. (Contributed by NM, 5-Aug-1993.)
Hypotheses
Ref Expression
syl7bi.1
syl7bi.2
Assertion
Ref Expression
syl7bi

Proof of Theorem syl7bi
StepHypRef Expression
1 syl7bi.1 . . 3
21biimpi 186 . 2
3 syl7bi.2 . 2
42, 3syl7 63 1
Colors of variables: wff setvar class
Syntax hints:   wi 4   wb 176
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
This theorem is referenced by:  rspct  2948
  Copyright terms: Public domain W3C validator