Metamath Proof Explorer


Theorem ioorrnopnxr

Description: The indexed product of open intervals is an open set in ( RR^X ) . Similar to ioorrnopn but here unbounded intervals are allowed. (Contributed by Glauco Siliprandi, 8-Apr-2021)

Ref Expression
Hypotheses ioorrnopnxr.x φ X Fin
ioorrnopnxr.a φ A : X *
ioorrnopnxr.b φ B : X *
Assertion ioorrnopnxr φ i X A i B i TopOpen X

Proof

Step Hyp Ref Expression
1 ioorrnopnxr.x φ X Fin
2 ioorrnopnxr.a φ A : X *
3 ioorrnopnxr.b φ B : X *
4 p0ex V
5 4 prid2
6 5 a1i X =
7 ixpeq1 X = i X A i B i = i A i B i
8 ixp0x i A i B i =
9 8 a1i X = i A i B i =
10 7 9 eqtrd X = i X A i B i =
11 2fveq3 X = TopOpen X = TopOpen
12 rrxtopn0b TopOpen =
13 12 a1i X = TopOpen =
14 11 13 eqtrd X = TopOpen X =
15 10 14 eleq12d X = i X A i B i TopOpen X
16 6 15 mpbird X = i X A i B i TopOpen X
17 16 adantl φ X = i X A i B i TopOpen X
18 neqne ¬ X = X
19 18 adantl φ ¬ X = X
20 fveq2 i = j A i = A j
21 fveq2 i = j B i = B j
22 20 21 oveq12d i = j A i B i = A j B j
23 22 cbvixpv i X A i B i = j X A j B j
24 23 eleq2i f i X A i B i f j X A j B j
25 24 biimpi f i X A i B i f j X A j B j
26 25 adantl φ X f i X A i B i f j X A j B j
27 1 ad2antrr φ X f j X A j B j X Fin
28 2 ad2antrr φ X f j X A j B j A : X *
29 3 ad2antrr φ X f j X A j B j B : X *
30 24 biimpri f j X A j B j f i X A i B i
31 30 adantl φ X f j X A j B j f i X A i B i
32 fveq2 j = i A j = A i
33 32 eqeq1d j = i A j = −∞ A i = −∞
34 fveq2 j = i f j = f i
35 34 oveq1d j = i f j 1 = f i 1
36 33 35 32 ifbieq12d j = i if A j = −∞ f j 1 A j = if A i = −∞ f i 1 A i
37 36 cbvmptv j X if A j = −∞ f j 1 A j = i X if A i = −∞ f i 1 A i
38 fveq2 j = i B j = B i
39 38 eqeq1d j = i B j = +∞ B i = +∞
40 34 oveq1d j = i f j + 1 = f i + 1
41 39 40 38 ifbieq12d j = i if B j = +∞ f j + 1 B j = if B i = +∞ f i + 1 B i
42 41 cbvmptv j X if B j = +∞ f j + 1 B j = i X if B i = +∞ f i + 1 B i
43 eqid i X j X if A j = −∞ f j 1 A j i j X if B j = +∞ f j + 1 B j i = i X j X if A j = −∞ f j 1 A j i j X if B j = +∞ f j + 1 B j i
44 27 28 29 31 37 42 43 ioorrnopnxrlem φ X f j X A j B j v TopOpen X f v v i X A i B i
45 26 44 syldan φ X f i X A i B i v TopOpen X f v v i X A i B i
46 45 ralrimiva φ X f i X A i B i v TopOpen X f v v i X A i B i
47 eqid TopOpen X = TopOpen X
48 47 rrxtop X Fin TopOpen X Top
49 1 48 syl φ TopOpen X Top
50 49 adantr φ X TopOpen X Top
51 eltop2 TopOpen X Top i X A i B i TopOpen X f i X A i B i v TopOpen X f v v i X A i B i
52 50 51 syl φ X i X A i B i TopOpen X f i X A i B i v TopOpen X f v v i X A i B i
53 46 52 mpbird φ X i X A i B i TopOpen X
54 19 53 syldan φ ¬ X = i X A i B i TopOpen X
55 17 54 pm2.61dan φ i X A i B i TopOpen X