Theorem nfreuxy 2644

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

Hypotheses

Ref	Expression
nfreuxy.1	|- F/_ x A
nfreuxy.2	|- F/ x ph

Assertion

Ref	Expression
nfreuxy	|- F/ x E! y e. A ph

Distinct variable group:   x, y

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

Proof of Theorem nfreuxy

Step	Hyp	Ref	Expression
1		nftru 1459	. . 3 |- F/ y T.
2		nfreuxy.1	. . . 4 |- F/_ x A
3	2	a1i 9	. . 3 |- ( T. -> F/_ x A )
4		nfreuxy.2	. . . 4 |- F/ x ph
5	4	a1i 9	. . 3 |- ( T. -> F/ x ph )
6	1, 3, 5	nfreudxy 2643	. 2 |- ( T. -> F/ x E! y e. A ph )
7	6	mptru 1357	1 |- F/ x E! y e. A ph

Syntax hints:   T. wtru 1349   F/wnf 1453   F/_wnfc 2299   E!wreu 2450

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-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-tru 1351  df-nf 1454  df-sb 1756  df-eu 2022  df-cleq 2163  df-clel 2166  df-nfc 2301  df-reu 2455

This theorem is referenced by:  sbcreug  3035