Theorem nfra2xy 2406

Description: Not-free given two restricted quantifiers. (Contributed by Jim Kingdon, 20-Aug-2018.)

Assertion

Ref	Expression
nfra2xy	|- F/ y A. x e. A A. y e. B ph

Distinct variable groups:   x, y   y, A

Allowed substitution hints:   ph( x, y)   A( x)   B( x, y)

Proof of Theorem nfra2xy

Step	Hyp	Ref	Expression
1		nfcv 2219	. 2 |- F/_ y A
2		nfra1 2397	. 2 |- F/ y A. y e. B ph
3	1, 2	nfralxy 2402	1 |- F/ y A. x e. A A. y e. B ph

Syntax hints:   F/wnf 1389   A.wral 2348

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-4 1440  ax-17 1459  ax-ial 1467  ax-i5r 1468  ax-ext 2063

This theorem depends on definitions:  df-bi 115  df-tru 1287  df-nf 1390  df-cleq 2074  df-clel 2077  df-nfc 2208  df-ral 2353

This theorem is referenced by:  invdisj  3780  reusv3  4210