Theorem reueq1f 2671

Description: Equality theorem for restricted unique existential quantifier, with bound-variable hypotheses instead of distinct variable restrictions. (Contributed by NM, 5-Apr-2004.) (Revised by Andrew Salmon, 11-Jul-2011.)

Hypotheses

Ref	Expression
raleq1f.1	|- F/_ x A
raleq1f.2	|- F/_ x B

Assertion

Ref	Expression
reueq1f	|- ( A = B -> ( E! x e. A ph <-> E! x e. B ph ) )

Proof of Theorem reueq1f

Step	Hyp	Ref	Expression
1		raleq1f.1	. . . 4 |- F/_ x A
2		raleq1f.2	. . . 4 |- F/_ x B
3	1, 2	nfeq 2327	. . 3 |- F/ x A = B
4		eleq2 2241	. . . 4 |- ( A = B -> ( x e. A <-> x e. B ) )
5	4	anbi1d 465	. . 3 |- ( A = B -> ( ( x e. A /\ ph ) <-> ( x e. B /\ ph ) ) )
6	3, 5	eubid 2033	. 2 |- ( A = B -> ( E! x ( x e. A /\ ph ) <-> E! x ( x e. B /\ ph ) ) )
7		df-reu 2462	. 2 |- ( E! x e. A ph <-> E! x ( x e. A /\ ph ) )
8		df-reu 2462	. 2 |- ( E! x e. B ph <-> E! x ( x e. B /\ ph ) )
9	6, 7, 8	3bitr4g 223	1 |- ( A = B -> ( E! x e. A ph <-> E! x e. B ph ) )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   = wceq 1353   E!weu 2026   e. wcel 2148   F/_wnfc 2306   E!wreu 2457

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 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159

This theorem depends on definitions:  df-bi 117  df-tru 1356  df-nf 1461  df-sb 1763  df-eu 2029  df-cleq 2170  df-clel 2173  df-nfc 2308  df-reu 2462

This theorem is referenced by:  reueq1  2675