Proof of Theorem max0addsup
Step | Hyp | Ref
| Expression |
1 | | 0re 7920 |
. . . . . 6
⊢ 0 ∈
ℝ |
2 | | maxabs 11173 |
. . . . . 6
⊢ ((𝐴 ∈ ℝ ∧ 0 ∈
ℝ) → sup({𝐴, 0},
ℝ, < ) = (((𝐴 + 0)
+ (abs‘(𝐴 −
0))) / 2)) |
3 | 1, 2 | mpan2 423 |
. . . . 5
⊢ (𝐴 ∈ ℝ →
sup({𝐴, 0}, ℝ, < )
= (((𝐴 + 0) +
(abs‘(𝐴 − 0)))
/ 2)) |
4 | | recn 7907 |
. . . . . . . 8
⊢ (𝐴 ∈ ℝ → 𝐴 ∈
ℂ) |
5 | 4 | addid1d 8068 |
. . . . . . 7
⊢ (𝐴 ∈ ℝ → (𝐴 + 0) = 𝐴) |
6 | 4 | subid1d 8219 |
. . . . . . . 8
⊢ (𝐴 ∈ ℝ → (𝐴 − 0) = 𝐴) |
7 | 6 | fveq2d 5500 |
. . . . . . 7
⊢ (𝐴 ∈ ℝ →
(abs‘(𝐴 − 0)) =
(abs‘𝐴)) |
8 | 5, 7 | oveq12d 5871 |
. . . . . 6
⊢ (𝐴 ∈ ℝ → ((𝐴 + 0) + (abs‘(𝐴 − 0))) = (𝐴 + (abs‘𝐴))) |
9 | 8 | oveq1d 5868 |
. . . . 5
⊢ (𝐴 ∈ ℝ → (((𝐴 + 0) + (abs‘(𝐴 − 0))) / 2) = ((𝐴 + (abs‘𝐴)) / 2)) |
10 | 3, 9 | eqtrd 2203 |
. . . 4
⊢ (𝐴 ∈ ℝ →
sup({𝐴, 0}, ℝ, < )
= ((𝐴 + (abs‘𝐴)) / 2)) |
11 | | renegcl 8180 |
. . . . . 6
⊢ (𝐴 ∈ ℝ → -𝐴 ∈
ℝ) |
12 | | maxabs 11173 |
. . . . . 6
⊢ ((-𝐴 ∈ ℝ ∧ 0 ∈
ℝ) → sup({-𝐴,
0}, ℝ, < ) = (((-𝐴
+ 0) + (abs‘(-𝐴
− 0))) / 2)) |
13 | 11, 1, 12 | sylancl 411 |
. . . . 5
⊢ (𝐴 ∈ ℝ →
sup({-𝐴, 0}, ℝ, <
) = (((-𝐴 + 0) +
(abs‘(-𝐴 − 0)))
/ 2)) |
14 | 11 | recnd 7948 |
. . . . . . . 8
⊢ (𝐴 ∈ ℝ → -𝐴 ∈
ℂ) |
15 | 14 | addid1d 8068 |
. . . . . . 7
⊢ (𝐴 ∈ ℝ → (-𝐴 + 0) = -𝐴) |
16 | 14 | subid1d 8219 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℝ → (-𝐴 − 0) = -𝐴) |
17 | 16 | fveq2d 5500 |
. . . . . . . 8
⊢ (𝐴 ∈ ℝ →
(abs‘(-𝐴 − 0))
= (abs‘-𝐴)) |
18 | 4 | absnegd 11153 |
. . . . . . . 8
⊢ (𝐴 ∈ ℝ →
(abs‘-𝐴) =
(abs‘𝐴)) |
19 | 17, 18 | eqtrd 2203 |
. . . . . . 7
⊢ (𝐴 ∈ ℝ →
(abs‘(-𝐴 − 0))
= (abs‘𝐴)) |
20 | 15, 19 | oveq12d 5871 |
. . . . . 6
⊢ (𝐴 ∈ ℝ → ((-𝐴 + 0) + (abs‘(-𝐴 − 0))) = (-𝐴 + (abs‘𝐴))) |
21 | 20 | oveq1d 5868 |
. . . . 5
⊢ (𝐴 ∈ ℝ → (((-𝐴 + 0) + (abs‘(-𝐴 − 0))) / 2) = ((-𝐴 + (abs‘𝐴)) / 2)) |
22 | 13, 21 | eqtrd 2203 |
. . . 4
⊢ (𝐴 ∈ ℝ →
sup({-𝐴, 0}, ℝ, <
) = ((-𝐴 + (abs‘𝐴)) / 2)) |
23 | 10, 22 | oveq12d 5871 |
. . 3
⊢ (𝐴 ∈ ℝ →
(sup({𝐴, 0}, ℝ, <
) + sup({-𝐴, 0}, ℝ,
< )) = (((𝐴 +
(abs‘𝐴)) / 2) +
((-𝐴 + (abs‘𝐴)) / 2))) |
24 | 4 | abscld 11145 |
. . . . . 6
⊢ (𝐴 ∈ ℝ →
(abs‘𝐴) ∈
ℝ) |
25 | 24 | recnd 7948 |
. . . . 5
⊢ (𝐴 ∈ ℝ →
(abs‘𝐴) ∈
ℂ) |
26 | 4, 25 | addcld 7939 |
. . . 4
⊢ (𝐴 ∈ ℝ → (𝐴 + (abs‘𝐴)) ∈ ℂ) |
27 | 14, 25 | addcld 7939 |
. . . 4
⊢ (𝐴 ∈ ℝ → (-𝐴 + (abs‘𝐴)) ∈ ℂ) |
28 | | 2cnd 8951 |
. . . 4
⊢ (𝐴 ∈ ℝ → 2 ∈
ℂ) |
29 | | 2ap0 8971 |
. . . . 5
⊢ 2 #
0 |
30 | 29 | a1i 9 |
. . . 4
⊢ (𝐴 ∈ ℝ → 2 #
0) |
31 | 26, 27, 28, 30 | divdirapd 8746 |
. . 3
⊢ (𝐴 ∈ ℝ → (((𝐴 + (abs‘𝐴)) + (-𝐴 + (abs‘𝐴))) / 2) = (((𝐴 + (abs‘𝐴)) / 2) + ((-𝐴 + (abs‘𝐴)) / 2))) |
32 | 4, 25, 14, 25 | add4d 8088 |
. . . . 5
⊢ (𝐴 ∈ ℝ → ((𝐴 + (abs‘𝐴)) + (-𝐴 + (abs‘𝐴))) = ((𝐴 + -𝐴) + ((abs‘𝐴) + (abs‘𝐴)))) |
33 | 4 | negidd 8220 |
. . . . . 6
⊢ (𝐴 ∈ ℝ → (𝐴 + -𝐴) = 0) |
34 | 33 | oveq1d 5868 |
. . . . 5
⊢ (𝐴 ∈ ℝ → ((𝐴 + -𝐴) + ((abs‘𝐴) + (abs‘𝐴))) = (0 + ((abs‘𝐴) + (abs‘𝐴)))) |
35 | 25, 25 | addcld 7939 |
. . . . . 6
⊢ (𝐴 ∈ ℝ →
((abs‘𝐴) +
(abs‘𝐴)) ∈
ℂ) |
36 | 35 | addid2d 8069 |
. . . . 5
⊢ (𝐴 ∈ ℝ → (0 +
((abs‘𝐴) +
(abs‘𝐴))) =
((abs‘𝐴) +
(abs‘𝐴))) |
37 | 32, 34, 36 | 3eqtrd 2207 |
. . . 4
⊢ (𝐴 ∈ ℝ → ((𝐴 + (abs‘𝐴)) + (-𝐴 + (abs‘𝐴))) = ((abs‘𝐴) + (abs‘𝐴))) |
38 | 37 | oveq1d 5868 |
. . 3
⊢ (𝐴 ∈ ℝ → (((𝐴 + (abs‘𝐴)) + (-𝐴 + (abs‘𝐴))) / 2) = (((abs‘𝐴) + (abs‘𝐴)) / 2)) |
39 | 23, 31, 38 | 3eqtr2d 2209 |
. 2
⊢ (𝐴 ∈ ℝ →
(sup({𝐴, 0}, ℝ, <
) + sup({-𝐴, 0}, ℝ,
< )) = (((abs‘𝐴) +
(abs‘𝐴)) /
2)) |
40 | 25 | 2timesd 9120 |
. . 3
⊢ (𝐴 ∈ ℝ → (2
· (abs‘𝐴)) =
((abs‘𝐴) +
(abs‘𝐴))) |
41 | 40 | oveq1d 5868 |
. 2
⊢ (𝐴 ∈ ℝ → ((2
· (abs‘𝐴)) /
2) = (((abs‘𝐴) +
(abs‘𝐴)) /
2)) |
42 | 25, 28, 30 | divcanap3d 8712 |
. 2
⊢ (𝐴 ∈ ℝ → ((2
· (abs‘𝐴)) /
2) = (abs‘𝐴)) |
43 | 39, 41, 42 | 3eqtr2d 2209 |
1
⊢ (𝐴 ∈ ℝ →
(sup({𝐴, 0}, ℝ, <
) + sup({-𝐴, 0}, ℝ,
< )) = (abs‘𝐴)) |