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Theorem nfcvf2 2281
Description: If  x and  y are distinct, then  y is not free in 
x. (Contributed by Mario Carneiro, 5-Dec-2016.)
Assertion
Ref Expression
nfcvf2  |-  ( -. 
A. x  x  =  y  ->  F/_ y x )

Proof of Theorem nfcvf2
StepHypRef Expression
1 nfcvf 2280 . 2  |-  ( -. 
A. y  y  =  x  ->  F/_ y x )
21naecoms 1687 1  |-  ( -. 
A. x  x  =  y  ->  F/_ y x )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4   A.wal 1314   F/_wnfc 2245
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 588  ax-in2 589  ax-io 683  ax-5 1408  ax-7 1409  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-8 1467  ax-10 1468  ax-11 1469  ax-i12 1470  ax-bndl 1471  ax-4 1472  ax-17 1491  ax-i9 1495  ax-ial 1499  ax-i5r 1500  ax-ext 2099
This theorem depends on definitions:  df-bi 116  df-tru 1319  df-fal 1322  df-nf 1422  df-sb 1721  df-cleq 2110  df-clel 2113  df-nfc 2247
This theorem is referenced by: (None)
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