Theorem nfra2xy 2550

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 2350	. 2 |- F/_ y A
2		nfra1 2539	. 2 |- F/ y A. y e. B ph
3	1, 2	nfralxy 2546	1 |- F/ y A. x e. A A. y e. B ph

Syntax hints:   F/wnf 1484   A.wral 2486

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 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-4 1534  ax-17 1550  ax-ial 1558  ax-i5r 1559  ax-ext 2189

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-cleq 2200  df-clel 2203  df-nfc 2339  df-ral 2491

This theorem is referenced by:  invdisj  4052  reusv3  4525