Metamath Proof Explorer


Theorem fourierdlem27

Description: A partition open interval is a subset of the partitioned open interval. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses fourierdlem27.a φ A *
fourierdlem27.b φ B *
fourierdlem27.q φ Q : 0 M A B
fourierdlem27.i φ I 0 ..^ M
Assertion fourierdlem27 φ Q I Q I + 1 A B

Proof

Step Hyp Ref Expression
1 fourierdlem27.a φ A *
2 fourierdlem27.b φ B *
3 fourierdlem27.q φ Q : 0 M A B
4 fourierdlem27.i φ I 0 ..^ M
5 1 adantr φ x Q I Q I + 1 A *
6 2 adantr φ x Q I Q I + 1 B *
7 elioore x Q I Q I + 1 x
8 7 adantl φ x Q I Q I + 1 x
9 iccssxr A B *
10 elfzofz I 0 ..^ M I 0 M
11 4 10 syl φ I 0 M
12 3 11 ffvelrnd φ Q I A B
13 9 12 sseldi φ Q I *
14 13 adantr φ x Q I Q I + 1 Q I *
15 8 rexrd φ x Q I Q I + 1 x *
16 iccgelb A * B * Q I A B A Q I
17 1 2 12 16 syl3anc φ A Q I
18 17 adantr φ x Q I Q I + 1 A Q I
19 fzofzp1 I 0 ..^ M I + 1 0 M
20 4 19 syl φ I + 1 0 M
21 3 20 ffvelrnd φ Q I + 1 A B
22 9 21 sseldi φ Q I + 1 *
23 22 adantr φ x Q I Q I + 1 Q I + 1 *
24 simpr φ x Q I Q I + 1 x Q I Q I + 1
25 ioogtlb Q I * Q I + 1 * x Q I Q I + 1 Q I < x
26 14 23 24 25 syl3anc φ x Q I Q I + 1 Q I < x
27 5 14 15 18 26 xrlelttrd φ x Q I Q I + 1 A < x
28 iooltub Q I * Q I + 1 * x Q I Q I + 1 x < Q I + 1
29 14 23 24 28 syl3anc φ x Q I Q I + 1 x < Q I + 1
30 iccleub A * B * Q I + 1 A B Q I + 1 B
31 1 2 21 30 syl3anc φ Q I + 1 B
32 31 adantr φ x Q I Q I + 1 Q I + 1 B
33 15 23 6 29 32 xrltletrd φ x Q I Q I + 1 x < B
34 5 6 8 27 33 eliood φ x Q I Q I + 1 x A B
35 34 ralrimiva φ x Q I Q I + 1 x A B
36 dfss3 Q I Q I + 1 A B x Q I Q I + 1 x A B
37 35 36 sylibr φ Q I Q I + 1 A B