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Theorem nfrab1 2791
Description: The abstraction variable in a restricted class abstraction isn't free. (Contributed by NM, 19-Mar-1997.)
Assertion
Ref Expression
nfrab1 x{x A φ}

Proof of Theorem nfrab1
StepHypRef Expression
1 df-rab 2623 . 2 {x A φ} = {x (x A φ)}
2 nfab1 2491 . 2 x{x (x A φ)}
31, 2nfcxfr 2486 1 x{x A φ}
Colors of variables: wff setvar class
Syntax hints:   wa 358   wcel 1710  {cab 2339  wnfc 2476  {crab 2618
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334
This theorem depends on definitions:  df-bi 177  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-rab 2623
This theorem is referenced by: (None)
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