Theorem nfreudxy 2661

Description: Not-free deduction for restricted uniqueness. This is a version where x and y are distinct. (Contributed by Jim Kingdon, 6-Jun-2018.)

Hypotheses

Ref	Expression
nfreudxy.1	|- F/ y ph
nfreudxy.2	|- ( ph -> F/_ x A )
nfreudxy.3	|- ( ph -> F/ x ps )

Assertion

Ref	Expression
nfreudxy	|- ( ph -> F/ x E! y e. A ps )

Distinct variable group:   x, y

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

Proof of Theorem nfreudxy

Step	Hyp	Ref	Expression
1		nfreudxy.1	. . 3 |- F/ y ph
2		nfcv 2329	. . . . . 6 |- F/_ x y
3	2	a1i 9	. . . . 5 |- ( ph -> F/_ x y )
4		nfreudxy.2	. . . . 5 |- ( ph -> F/_ x A )
5	3, 4	nfeld 2345	. . . 4 |- ( ph -> F/ x y e. A )
6		nfreudxy.3	. . . 4 |- ( ph -> F/ x ps )
7	5, 6	nfand 1578	. . 3 |- ( ph -> F/ x ( y e. A /\ ps ) )
8	1, 7	nfeud 2052	. 2 |- ( ph -> F/ x E! y ( y e. A /\ ps ) )
9		df-reu 2472	. . 3 |- ( E! y e. A ps <-> E! y ( y e. A /\ ps ) )
10	9	nfbii 1483	. 2 |- ( F/ x E! y e. A ps <-> F/ x E! y ( y e. A /\ ps ) )
11	8, 10	sylibr 134	1 |- ( ph -> F/ x E! y e. A ps )

Syntax hints:   -> wi 4   /\ wa 104   F/wnf 1470   E!weu 2036   e. wcel 2158   F/_wnfc 2316   E!wreu 2467

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-io 710  ax-5 1457  ax-7 1458  ax-gen 1459  ax-ie1 1503  ax-ie2 1504  ax-8 1514  ax-10 1515  ax-11 1516  ax-i12 1517  ax-bndl 1519  ax-4 1520  ax-17 1536  ax-i9 1540  ax-ial 1544  ax-i5r 1545  ax-ext 2169

This theorem depends on definitions:  df-bi 117  df-tru 1366  df-nf 1471  df-sb 1773  df-eu 2039  df-cleq 2180  df-clel 2183  df-nfc 2318  df-reu 2472

This theorem is referenced by:  nfreuxy  2662