Proof of Theorem xrmaxifle
Step | Hyp | Ref
| Expression |
1 | | pnfge 9733 |
. . . 4
⊢ (𝐴 ∈ ℝ*
→ 𝐴 ≤
+∞) |
2 | 1 | ad2antrr 485 |
. . 3
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ 𝐵 = +∞) → 𝐴 ≤ +∞) |
3 | | simpr 109 |
. . . 4
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ 𝐵 = +∞) → 𝐵 = +∞) |
4 | 3 | iftrued 3532 |
. . 3
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ 𝐵 = +∞) → if(𝐵 = +∞, +∞, if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))))) =
+∞) |
5 | 2, 4 | breqtrrd 4015 |
. 2
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ 𝐵 = +∞) → 𝐴 ≤ if(𝐵 = +∞, +∞, if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))))) |
6 | | xrleid 9744 |
. . . . . 6
⊢ (𝐴 ∈ ℝ*
→ 𝐴 ≤ 𝐴) |
7 | 6 | ad3antrrr 489 |
. . . . 5
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ 𝐵 = -∞) → 𝐴 ≤ 𝐴) |
8 | | simpr 109 |
. . . . . 6
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ 𝐵 = -∞) → 𝐵 = -∞) |
9 | 8 | iftrued 3532 |
. . . . 5
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ 𝐵 = -∞) → if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))) = 𝐴) |
10 | 7, 9 | breqtrrd 4015 |
. . . 4
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ 𝐵 = -∞) → 𝐴 ≤ if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))))) |
11 | 1 | ad4antr 491 |
. . . . . . 7
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ 𝐴 = +∞) → 𝐴 ≤ +∞) |
12 | | simpr 109 |
. . . . . . . 8
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ 𝐴 = +∞) → 𝐴 = +∞) |
13 | 12 | iftrued 3532 |
. . . . . . 7
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ 𝐴 = +∞) → if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))) =
+∞) |
14 | 11, 13 | breqtrrd 4015 |
. . . . . 6
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ 𝐴 = +∞) → 𝐴 ≤ if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))) |
15 | | mnfle 9736 |
. . . . . . . . . 10
⊢ (𝐵 ∈ ℝ*
→ -∞ ≤ 𝐵) |
16 | 15 | ad5antlr 494 |
. . . . . . . . 9
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ 𝐴 = -∞) → -∞ ≤ 𝐵) |
17 | | simpr 109 |
. . . . . . . . 9
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ 𝐴 = -∞) → 𝐴 = -∞) |
18 | 17 | iftrued 3532 |
. . . . . . . . 9
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ 𝐴 = -∞) → if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )) = 𝐵) |
19 | 16, 17, 18 | 3brtr4d 4019 |
. . . . . . . 8
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ 𝐴 = -∞) → 𝐴 ≤ if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))) |
20 | | simplr 525 |
. . . . . . . . . . 11
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → ¬ 𝐴 = +∞) |
21 | | simpr 109 |
. . . . . . . . . . 11
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → ¬ 𝐴 = -∞) |
22 | | elxr 9720 |
. . . . . . . . . . . . 13
⊢ (𝐴 ∈ ℝ*
↔ (𝐴 ∈ ℝ
∨ 𝐴 = +∞ ∨
𝐴 =
-∞)) |
23 | 22 | biimpi 119 |
. . . . . . . . . . . 12
⊢ (𝐴 ∈ ℝ*
→ (𝐴 ∈ ℝ
∨ 𝐴 = +∞ ∨
𝐴 =
-∞)) |
24 | 23 | ad5antr 493 |
. . . . . . . . . . 11
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → (𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞)) |
25 | 20, 21, 24 | ecase23d 1345 |
. . . . . . . . . 10
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → 𝐴 ∈ ℝ) |
26 | | simpr 109 |
. . . . . . . . . . . 12
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) → ¬ 𝐵 = +∞) |
27 | 26 | ad3antrrr 489 |
. . . . . . . . . . 11
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → ¬ 𝐵 = +∞) |
28 | | simpr 109 |
. . . . . . . . . . . 12
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) → ¬ 𝐵 = -∞) |
29 | 28 | ad2antrr 485 |
. . . . . . . . . . 11
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → ¬ 𝐵 = -∞) |
30 | | elxr 9720 |
. . . . . . . . . . . . 13
⊢ (𝐵 ∈ ℝ*
↔ (𝐵 ∈ ℝ
∨ 𝐵 = +∞ ∨
𝐵 =
-∞)) |
31 | 30 | biimpi 119 |
. . . . . . . . . . . 12
⊢ (𝐵 ∈ ℝ*
→ (𝐵 ∈ ℝ
∨ 𝐵 = +∞ ∨
𝐵 =
-∞)) |
32 | 31 | ad5antlr 494 |
. . . . . . . . . . 11
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → (𝐵 ∈ ℝ ∨ 𝐵 = +∞ ∨ 𝐵 = -∞)) |
33 | 27, 29, 32 | ecase23d 1345 |
. . . . . . . . . 10
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → 𝐵 ∈ ℝ) |
34 | | maxle1 11162 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → 𝐴 ≤ sup({𝐴, 𝐵}, ℝ, < )) |
35 | 25, 33, 34 | syl2anc 409 |
. . . . . . . . 9
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → 𝐴 ≤ sup({𝐴, 𝐵}, ℝ, < )) |
36 | 21 | iffalsed 3535 |
. . . . . . . . 9
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )) = sup({𝐴, 𝐵}, ℝ, < )) |
37 | 35, 36 | breqtrrd 4015 |
. . . . . . . 8
⊢
((((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) ∧ ¬ 𝐴 = -∞) → 𝐴 ≤ if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))) |
38 | | xrmnfdc 9787 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℝ*
→ DECID 𝐴 = -∞) |
39 | | exmiddc 831 |
. . . . . . . . . 10
⊢
(DECID 𝐴 = -∞ → (𝐴 = -∞ ∨ ¬ 𝐴 = -∞)) |
40 | 38, 39 | syl 14 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℝ*
→ (𝐴 = -∞ ∨
¬ 𝐴 =
-∞)) |
41 | 40 | ad4antr 491 |
. . . . . . . 8
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) → (𝐴 = -∞ ∨ ¬ 𝐴 = -∞)) |
42 | 19, 37, 41 | mpjaodan 793 |
. . . . . . 7
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) → 𝐴 ≤ if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))) |
43 | | simpr 109 |
. . . . . . . 8
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) → ¬ 𝐴 = +∞) |
44 | 43 | iffalsed 3535 |
. . . . . . 7
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) → if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))) = if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))) |
45 | 42, 44 | breqtrrd 4015 |
. . . . . 6
⊢
(((((𝐴 ∈
ℝ* ∧ 𝐵
∈ ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) ∧ ¬ 𝐴 = +∞) → 𝐴 ≤ if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))) |
46 | | xrpnfdc 9786 |
. . . . . . . 8
⊢ (𝐴 ∈ ℝ*
→ DECID 𝐴 = +∞) |
47 | | exmiddc 831 |
. . . . . . . 8
⊢
(DECID 𝐴 = +∞ → (𝐴 = +∞ ∨ ¬ 𝐴 = +∞)) |
48 | 46, 47 | syl 14 |
. . . . . . 7
⊢ (𝐴 ∈ ℝ*
→ (𝐴 = +∞ ∨
¬ 𝐴 =
+∞)) |
49 | 48 | ad3antrrr 489 |
. . . . . 6
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) → (𝐴 = +∞ ∨ ¬ 𝐴 = +∞)) |
50 | 14, 45, 49 | mpjaodan 793 |
. . . . 5
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) → 𝐴 ≤ if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))) |
51 | 28 | iffalsed 3535 |
. . . . 5
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) → if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))) = if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))) |
52 | 50, 51 | breqtrrd 4015 |
. . . 4
⊢ ((((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) ∧ ¬ 𝐵 = -∞) → 𝐴 ≤ if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))))) |
53 | | xrmnfdc 9787 |
. . . . . 6
⊢ (𝐵 ∈ ℝ*
→ DECID 𝐵 = -∞) |
54 | | exmiddc 831 |
. . . . . 6
⊢
(DECID 𝐵 = -∞ → (𝐵 = -∞ ∨ ¬ 𝐵 = -∞)) |
55 | 53, 54 | syl 14 |
. . . . 5
⊢ (𝐵 ∈ ℝ*
→ (𝐵 = -∞ ∨
¬ 𝐵 =
-∞)) |
56 | 55 | ad2antlr 486 |
. . . 4
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) → (𝐵 = -∞ ∨ ¬ 𝐵 = -∞)) |
57 | 10, 52, 56 | mpjaodan 793 |
. . 3
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) → 𝐴 ≤ if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))))) |
58 | 26 | iffalsed 3535 |
. . 3
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) → if(𝐵 = +∞, +∞, if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))))) = if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < ))))) |
59 | 57, 58 | breqtrrd 4015 |
. 2
⊢ (((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) ∧ ¬ 𝐵 = +∞) → 𝐴 ≤ if(𝐵 = +∞, +∞, if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))))) |
60 | | xrpnfdc 9786 |
. . . 4
⊢ (𝐵 ∈ ℝ*
→ DECID 𝐵 = +∞) |
61 | | exmiddc 831 |
. . . 4
⊢
(DECID 𝐵 = +∞ → (𝐵 = +∞ ∨ ¬ 𝐵 = +∞)) |
62 | 60, 61 | syl 14 |
. . 3
⊢ (𝐵 ∈ ℝ*
→ (𝐵 = +∞ ∨
¬ 𝐵 =
+∞)) |
63 | 62 | adantl 275 |
. 2
⊢ ((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) → (𝐵 = +∞ ∨ ¬ 𝐵 = +∞)) |
64 | 5, 59, 63 | mpjaodan 793 |
1
⊢ ((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) → 𝐴 ≤ if(𝐵 = +∞, +∞, if(𝐵 = -∞, 𝐴, if(𝐴 = +∞, +∞, if(𝐴 = -∞, 𝐵, sup({𝐴, 𝐵}, ℝ, < )))))) |