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

Proof of Theorem nfre1
StepHypRef Expression
1 df-rex 2534 . 2 (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑))
2 nfe1 1549 . 2 Ⅎ𝑥∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)
31, 2nfxfr 1527 1 Ⅎ𝑥∃𝑥 ∈ 𝐴 𝜑
Colors of variables:    wff set class
This proof depends on syntax axioms:   ∧ wa 104  Ⅎwnf 1513  ∃wex 1545   ∈ wcel 2209  ∃wrex 2529
This proof depends on 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 proof depends on definitions:  df-bi 117  df-nf 1514  df-rex 2534
This theorem is used by:  r19.29an  2693  nfiu1  4042  fun11iun  5660  eusvobj2  6071  fodjuomnilemdc  7485  ismkvnex  7496  prarloclem3step  7864  prmuloc2  7935  ltexprlemm  7968  caucvgprprlemaddq  8076  caucvgsrlemgt1  8163  axpre-suploclemres  8269  supinfneg  10005  infsupneg  10006  lbzbi  10026  divalglemeunn  12707  divalglemeuneg  12709  bezoutlemmain  12794  bezout  12807  lss1d  14804  pw1nct  17199  isomninnlem  17245  trirec0  17260  ismkvnnlem  17269
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