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Theorem nfor 1836
Description: If is not free in and , it is not free in . (Contributed by Mario Carneiro, 11-Aug-2016.)
Hypotheses
Ref Expression
nf.1  F/
nf.2  F/
Assertion
Ref Expression
nfor  F/

Proof of Theorem nfor
StepHypRef Expression
1 df-or 359 . 2
2 nf.1 . . . 4  F/
32nfn 1793 . . 3  F/
4 nf.2 . . 3  F/
53, 4nfim 1813 . 2  F/
61, 5nfxfr 1570 1  F/
Colors of variables: wff setvar class
Syntax hints:   wn 3   wi 4   wo 357   F/wnf 1544
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-11 1746
This theorem depends on definitions:  df-bi 177  df-or 359  df-tru 1319  df-ex 1542  df-nf 1545
This theorem is referenced by:  nf3or  1837  axi12  2333  nfpr  3773
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