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Theorem nfre1 2593
Description: 𝑥 is not free in 𝑥𝐴𝜑. (Contributed by NM, 19-Mar-1997.) (Revised by Mario Carneiro, 7-Oct-2016.)
Assertion
Ref Expression
nfre1 𝑥𝑥𝐴 𝜑

Proof of Theorem nfre1
StepHypRef Expression
1 df-rex 2534 . 2 (∃𝑥𝐴 𝜑 ↔ ∃𝑥(𝑥𝐴𝜑))
2 nfe1 1549 . 2 𝑥𝑥(𝑥𝐴𝜑)
31, 2nfxfr 1527 1 𝑥𝑥𝐴 𝜑
Colors of variables: wff set class
Syntax hints:  wa 104  wnf 1513  wex 1545  wcel 2209  wrex 2529
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1500  ax-gen 1502  ax-ie1 1546
This theorem depends on definitions:  df-bi 117  df-nf 1514  df-rex 2534
This theorem is referenced by:  r19.29an  2693  nfiu1  4037  fun11iun  5655  eusvobj2  6061  fodjuomnilemdc  7474  ismkvnex  7485  prarloclem3step  7853  prmuloc2  7924  ltexprlemm  7957  caucvgprprlemaddq  8065  caucvgsrlemgt1  8152  axpre-suploclemres  8258  supinfneg  9974  infsupneg  9975  lbzbi  9995  divalglemeunn  12666  divalglemeuneg  12668  bezoutlemmain  12753  bezout  12766  lss1d  14692  pw1nct  16947  isomninnlem  16984  trirec0  16998  ismkvnnlem  17007
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