ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  nfre1 Unicode version

Theorem nfre1 2365
Description:  x is not free in  E. x  e.  A ph. (Contributed by NM, 19-Mar-1997.) (Revised by Mario Carneiro, 7-Oct-2016.)
Assertion
Ref Expression
nfre1  |-  F/ x E. x  e.  A  ph

Proof of Theorem nfre1
StepHypRef Expression
1 df-rex 2312 . 2  |-  ( E. x  e.  A  ph  <->  E. x ( x  e.  A  /\  ph )
)
2 nfe1 1385 . 2  |-  F/ x E. x ( x  e.  A  /\  ph )
31, 2nfxfr 1363 1  |-  F/ x E. x  e.  A  ph
Colors of variables: wff set class
Syntax hints:    /\ wa 97   F/wnf 1349   E.wex 1381    e. wcel 1393   E.wrex 2307
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-gen 1338  ax-ie1 1382
This theorem depends on definitions:  df-bi 110  df-nf 1350  df-rex 2312
This theorem is referenced by:  nfiu1  3687  fun11iun  5147  eusvobj2  5498  prarloclem3step  6594  prmuloc2  6665  ltexprlemm  6698  caucvgprprlemaddq  6806  caucvgsrlemgt1  6879  lbzbi  8551
  Copyright terms: Public domain W3C validator