Theorem rmo2ilem 3054

Description: Condition implying restricted at-most-one quantifier. (Contributed by Jim Kingdon, 14-Jul-2018.)

Hypothesis

Ref	Expression
rmo2.1	|- F/ y ph

Assertion

Ref	Expression
rmo2ilem	|- ( E. y A. x e. A ( ph -> x = y ) -> E* x e. A ph )

Distinct variable group:   x, y, A

Allowed substitution hints:   ph( x, y)

Proof of Theorem rmo2ilem

Step	Hyp	Ref	Expression
1		impexp 263	. . . . 5 |- ( ( ( x e. A /\ ph ) -> x = y ) <-> ( x e. A -> ( ph -> x = y ) ) )
2	1	albii 1470	. . . 4 |- ( A. x ( ( x e. A /\ ph ) -> x = y ) <-> A. x ( x e. A -> ( ph -> x = y ) ) )
3		df-ral 2460	. . . 4 |- ( A. x e. A ( ph -> x = y ) <-> A. x ( x e. A -> ( ph -> x = y ) ) )
4	2, 3	bitr4i 187	. . 3 |- ( A. x ( ( x e. A /\ ph ) -> x = y ) <-> A. x e. A ( ph -> x = y ) )
5	4	exbii 1605	. 2 |- ( E. y A. x ( ( x e. A /\ ph ) -> x = y ) <-> E. y A. x e. A ( ph -> x = y ) )
6		nfv 1528	. . . . 5 |- F/ y x e. A
7		rmo2.1	. . . . 5 |- F/ y ph
8	6, 7	nfan 1565	. . . 4 |- F/ y ( x e. A /\ ph )
9	8	mo2r 2078	. . 3 |- ( E. y A. x ( ( x e. A /\ ph ) -> x = y ) -> E* x ( x e. A /\ ph ) )
10		df-rmo 2463	. . 3 |- ( E* x e. A ph <-> E* x ( x e. A /\ ph ) )
11	9, 10	sylibr 134	. 2 |- ( E. y A. x ( ( x e. A /\ ph ) -> x = y ) -> E* x e. A ph )
12	5, 11	sylbir 135	1 |- ( E. y A. x e. A ( ph -> x = y ) -> E* x e. A ph )

Syntax hints:   -> wi 4   /\ wa 104   A.wal 1351   = wceq 1353   F/wnf 1460   E.wex 1492   E*wmo 2027   e. wcel 2148   A.wral 2455   E*wrmo 2458

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

This theorem depends on definitions:  df-bi 117  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-ral 2460  df-rmo 2463

This theorem is referenced by:  rmo2i  3055