Metamath Proof Explorer


Theorem fdvposle

Description: Functions with a nonnegative derivative, i.e. monotonously growing functions, preserve ordering. (Contributed by Thierry Arnoux, 20-Dec-2021)

Ref Expression
Hypotheses fdvposlt.d E = C D
fdvposlt.a φ A E
fdvposlt.b φ B E
fdvposlt.f φ F : E
fdvposlt.c φ F : E cn
fdvposle.le φ A B
fdvposle.1 φ x A B 0 F x
Assertion fdvposle φ F A F B

Proof

Step Hyp Ref Expression
1 fdvposlt.d E = C D
2 fdvposlt.a φ A E
3 fdvposlt.b φ B E
4 fdvposlt.f φ F : E
5 fdvposlt.c φ F : E cn
6 fdvposle.le φ A B
7 fdvposle.1 φ x A B 0 F x
8 ioossicc A B A B
9 8 a1i φ A B A B
10 ioombl A B dom vol
11 10 a1i φ A B dom vol
12 cncff F : E cn F : E
13 5 12 syl φ F : E
14 13 adantr φ x A B F : E
15 1 2 3 fct2relem φ A B E
16 15 sselda φ x A B x E
17 14 16 ffvelrnd φ x A B F x
18 ioossre C D
19 1 18 eqsstri E
20 19 2 sseldi φ A
21 19 3 sseldi φ B
22 ax-resscn
23 ssid
24 cncfss A B cn A B cn
25 22 23 24 mp2an A B cn A B cn
26 13 15 feqresmpt φ F A B = x A B F x
27 rescncf A B E F : E cn F A B : A B cn
28 15 5 27 sylc φ F A B : A B cn
29 26 28 eqeltrrd φ x A B F x : A B cn
30 25 29 sseldi φ x A B F x : A B cn
31 cniccibl A B x A B F x : A B cn x A B F x 𝐿 1
32 20 21 30 31 syl3anc φ x A B F x 𝐿 1
33 9 11 17 32 iblss φ x A B F x 𝐿 1
34 13 adantr φ x A B F : E
35 9 sselda φ x A B x A B
36 35 16 syldan φ x A B x E
37 34 36 ffvelrnd φ x A B F x
38 33 37 7 itgge0 φ 0 A B F x dx
39 fss F : E F : E
40 4 22 39 sylancl φ F : E
41 cncfss E cn E cn
42 22 23 41 mp2an E cn E cn
43 42 5 sseldi φ F : E cn
44 1 2 3 6 40 43 ftc2re φ A B F x dx = F B F A
45 38 44 breqtrd φ 0 F B F A
46 4 3 ffvelrnd φ F B
47 4 2 ffvelrnd φ F A
48 46 47 subge0d φ 0 F B F A F A F B
49 45 48 mpbid φ F A F B