Theorem elioo2 8790

Description: Membership in an open interval of extended reals. (Contributed by NM, 6-Feb-2007.)

Assertion

Ref	Expression
elioo2	|- ( ( A e. RR* /\ B e. RR* ) -> ( C e. ( A (,) B ) <-> ( C e. RR /\ A < C /\ C < B ) ) )

Proof of Theorem elioo2

Dummy variable x is distinct from all other variables.

Step	Hyp	Ref	Expression
1		iooval2 8784	. . 3 |- ( ( A e. RR* /\ B e. RR* ) -> ( A (,) B ) = { x e. RR | ( A < x /\ x < B ) } )
2	1	eleq2d 2107	. 2 |- ( ( A e. RR* /\ B e. RR* ) -> ( C e. ( A (,) B ) <-> C e. { x e. RR | ( A < x /\ x < B ) } ) )
3		breq2 3768	. . . . 5 |- ( x = C -> ( A < x <-> A < C ) )
4		breq1 3767	. . . . 5 |- ( x = C -> ( x < B <-> C < B ) )
5	3, 4	anbi12d 442	. . . 4 |- ( x = C -> ( ( A < x /\ x < B ) <-> ( A < C /\ C < B ) ) )
6	5	elrab 2698	. . 3 |- ( C e. { x e. RR | ( A < x /\ x < B ) } <-> ( C e. RR /\ ( A < C /\ C < B ) ) )
7		3anass 889	. . 3 |- ( ( C e. RR /\ A < C /\ C < B ) <-> ( C e. RR /\ ( A < C /\ C < B ) ) )
8	6, 7	bitr4i 176	. 2 |- ( C e. { x e. RR | ( A < x /\ x < B ) } <-> ( C e. RR /\ A < C /\ C < B ) )
9	2, 8	syl6bb 185	1 |- ( ( A e. RR* /\ B e. RR* ) -> ( C e. ( A (,) B ) <-> ( C e. RR /\ A < C /\ C < B ) ) )

Syntax hints:   -> wi 4   /\ wa 97   <-> wb 98   /\ w3a 885   = wceq 1243   e. wcel 1393   {crab 2310   class class class wbr 3764  (class class class)co 5512   RRcr 6888   RR*cxr 7059   < clt 7060   (,)cioo 8757

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 544  ax-in2 545  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-13 1404  ax-14 1405  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022  ax-sep 3875  ax-pow 3927  ax-pr 3944  ax-un 4170  ax-setind 4262  ax-cnex 6975  ax-resscn 6976  ax-pre-ltirr 6996  ax-pre-ltwlin 6997  ax-pre-lttrn 6998

This theorem depends on definitions:  df-bi 110  df-3or 886  df-3an 887  df-tru 1246  df-fal 1249  df-nf 1350  df-sb 1646  df-eu 1903  df-mo 1904  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-ne 2206  df-nel 2207  df-ral 2311  df-rex 2312  df-rab 2315  df-v 2559  df-sbc 2765  df-dif 2920  df-un 2922  df-in 2924  df-ss 2931  df-pw 3361  df-sn 3381  df-pr 3382  df-op 3384  df-uni 3581  df-br 3765  df-opab 3819  df-id 4030  df-po 4033  df-iso 4034  df-xp 4351  df-rel 4352  df-cnv 4353  df-co 4354  df-dm 4355  df-iota 4867  df-fun 4904  df-fv 4910  df-ov 5515  df-oprab 5516  df-mpt2 5517  df-pnf 7062  df-mnf 7063  df-xr 7064  df-ltxr 7065  df-le 7066  df-ioo 8761

This theorem is referenced by:  eliooord  8797  elioopnf  8836  elioomnf  8837