ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  nfrexxy Unicode version

Theorem nfrexxy 2514
Description: Not-free for restricted existential quantification where  x and  y are distinct. See nfrexya 2516 for a version with  y and 
A distinct instead. (Contributed by Jim Kingdon, 30-May-2018.)
Hypotheses
Ref Expression
nfralxy.1  |-  F/_ x A
nfralxy.2  |-  F/ x ph
Assertion
Ref Expression
nfrexxy  |-  F/ x E. y  e.  A  ph
Distinct variable group:    x, y
Allowed substitution hints:    ph( x, y)    A( x, y)

Proof of Theorem nfrexxy
StepHypRef Expression
1 nftru 1464 . . 3  |-  F/ y T.
2 nfralxy.1 . . . 4  |-  F/_ x A
32a1i 9 . . 3  |-  ( T. 
->  F/_ x A )
4 nfralxy.2 . . . 4  |-  F/ x ph
54a1i 9 . . 3  |-  ( T. 
->  F/ x ph )
61, 3, 5nfrexdxy 2509 . 2  |-  ( T. 
->  F/ x E. y  e.  A  ph )
76mptru 1362 1  |-  F/ x E. y  e.  A  ph
Colors of variables: wff set class
Syntax hints:   T. wtru 1354   F/wnf 1458   F/_wnfc 2304   E.wrex 2454
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 1445  ax-7 1446  ax-gen 1447  ax-ie1 1491  ax-ie2 1492  ax-4 1508  ax-17 1524  ax-ial 1532  ax-i5r 1533  ax-ext 2157
This theorem depends on definitions:  df-bi 117  df-tru 1356  df-nf 1459  df-cleq 2168  df-clel 2171  df-nfc 2306  df-rex 2459
This theorem is referenced by:  r19.12  2581  sbcrext  3038  nfuni  3811  nfiunxy  3908  rexxpf  4767  abrexex2g  6111  abrexex2  6115  nfrecs  6298  fimaxre2  11203  nfsum  11333  nfcprod1  11530  nfcprod  11531  bezoutlemmain  11966  ctiunctlemfo  12407  bj-findis  14300  strcollnfALT  14307
  Copyright terms: Public domain W3C validator