Proof of Theorem sqreu
Step | Hyp | Ref
| Expression |
1 | | abscl 14990 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(abs‘𝐴) ∈
ℝ) |
2 | 1 | recnd 11003 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(abs‘𝐴) ∈
ℂ) |
3 | | subneg 11270 |
. . . . . . 7
⊢
(((abs‘𝐴)
∈ ℂ ∧ 𝐴
∈ ℂ) → ((abs‘𝐴) − -𝐴) = ((abs‘𝐴) + 𝐴)) |
4 | 2, 3 | mpancom 685 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
((abs‘𝐴) −
-𝐴) = ((abs‘𝐴) + 𝐴)) |
5 | 4 | eqeq1d 2740 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(((abs‘𝐴) −
-𝐴) = 0 ↔
((abs‘𝐴) + 𝐴) = 0)) |
6 | | negcl 11221 |
. . . . . 6
⊢ (𝐴 ∈ ℂ → -𝐴 ∈
ℂ) |
7 | 2, 6 | subeq0ad 11342 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(((abs‘𝐴) −
-𝐴) = 0 ↔
(abs‘𝐴) = -𝐴)) |
8 | 5, 7 | bitr3d 280 |
. . . 4
⊢ (𝐴 ∈ ℂ →
(((abs‘𝐴) + 𝐴) = 0 ↔ (abs‘𝐴) = -𝐴)) |
9 | | ax-icn 10930 |
. . . . . . 7
⊢ i ∈
ℂ |
10 | | absge0 14999 |
. . . . . . . . . . . 12
⊢ (𝐴 ∈ ℂ → 0 ≤
(abs‘𝐴)) |
11 | 1, 10 | jca 512 |
. . . . . . . . . . 11
⊢ (𝐴 ∈ ℂ →
((abs‘𝐴) ∈
ℝ ∧ 0 ≤ (abs‘𝐴))) |
12 | | eleq1 2826 |
. . . . . . . . . . . 12
⊢
((abs‘𝐴) =
-𝐴 → ((abs‘𝐴) ∈ ℝ ↔ -𝐴 ∈
ℝ)) |
13 | | breq2 5078 |
. . . . . . . . . . . 12
⊢
((abs‘𝐴) =
-𝐴 → (0 ≤
(abs‘𝐴) ↔ 0 ≤
-𝐴)) |
14 | 12, 13 | anbi12d 631 |
. . . . . . . . . . 11
⊢
((abs‘𝐴) =
-𝐴 →
(((abs‘𝐴) ∈
ℝ ∧ 0 ≤ (abs‘𝐴)) ↔ (-𝐴 ∈ ℝ ∧ 0 ≤ -𝐴))) |
15 | 11, 14 | syl5ib 243 |
. . . . . . . . . 10
⊢
((abs‘𝐴) =
-𝐴 → (𝐴 ∈ ℂ → (-𝐴 ∈ ℝ ∧ 0 ≤
-𝐴))) |
16 | 15 | impcom 408 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (-𝐴 ∈ ℝ ∧ 0 ≤ -𝐴)) |
17 | | resqrtcl 14965 |
. . . . . . . . 9
⊢ ((-𝐴 ∈ ℝ ∧ 0 ≤
-𝐴) →
(√‘-𝐴) ∈
ℝ) |
18 | 16, 17 | syl 17 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (√‘-𝐴) ∈
ℝ) |
19 | 18 | recnd 11003 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (√‘-𝐴) ∈
ℂ) |
20 | | mulcl 10955 |
. . . . . . 7
⊢ ((i
∈ ℂ ∧ (√‘-𝐴) ∈ ℂ) → (i ·
(√‘-𝐴)) ∈
ℂ) |
21 | 9, 19, 20 | sylancr 587 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (i ·
(√‘-𝐴)) ∈
ℂ) |
22 | | sqrtneglem 14978 |
. . . . . . . 8
⊢ ((-𝐴 ∈ ℝ ∧ 0 ≤
-𝐴) → (((i ·
(√‘-𝐴))↑2)
= --𝐴 ∧ 0 ≤
(ℜ‘(i · (√‘-𝐴))) ∧ (i · (i ·
(√‘-𝐴)))
∉ ℝ+)) |
23 | 16, 22 | syl 17 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (((i ·
(√‘-𝐴))↑2)
= --𝐴 ∧ 0 ≤
(ℜ‘(i · (√‘-𝐴))) ∧ (i · (i ·
(√‘-𝐴)))
∉ ℝ+)) |
24 | | negneg 11271 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℂ → --𝐴 = 𝐴) |
25 | 24 | adantr 481 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → --𝐴 = 𝐴) |
26 | 25 | eqeq2d 2749 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (((i ·
(√‘-𝐴))↑2)
= --𝐴 ↔ ((i ·
(√‘-𝐴))↑2)
= 𝐴)) |
27 | 26 | 3anbi1d 1439 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → ((((i ·
(√‘-𝐴))↑2)
= --𝐴 ∧ 0 ≤
(ℜ‘(i · (√‘-𝐴))) ∧ (i · (i ·
(√‘-𝐴)))
∉ ℝ+) ↔ (((i · (√‘-𝐴))↑2) = 𝐴 ∧ 0 ≤ (ℜ‘(i ·
(√‘-𝐴))) ∧
(i · (i · (√‘-𝐴))) ∉
ℝ+))) |
28 | 23, 27 | mpbid 231 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → (((i ·
(√‘-𝐴))↑2)
= 𝐴 ∧ 0 ≤
(ℜ‘(i · (√‘-𝐴))) ∧ (i · (i ·
(√‘-𝐴)))
∉ ℝ+)) |
29 | | oveq1 7282 |
. . . . . . . . 9
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
(𝑥↑2) = ((i ·
(√‘-𝐴))↑2)) |
30 | 29 | eqeq1d 2740 |
. . . . . . . 8
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
((𝑥↑2) = 𝐴 ↔ ((i ·
(√‘-𝐴))↑2)
= 𝐴)) |
31 | | fveq2 6774 |
. . . . . . . . 9
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
(ℜ‘𝑥) =
(ℜ‘(i · (√‘-𝐴)))) |
32 | 31 | breq2d 5086 |
. . . . . . . 8
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
(0 ≤ (ℜ‘𝑥)
↔ 0 ≤ (ℜ‘(i · (√‘-𝐴))))) |
33 | | oveq2 7283 |
. . . . . . . . 9
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
(i · 𝑥) = (i
· (i · (√‘-𝐴)))) |
34 | | neleq1 3054 |
. . . . . . . . 9
⊢ ((i
· 𝑥) = (i ·
(i · (√‘-𝐴))) → ((i · 𝑥) ∉ ℝ+ ↔ (i
· (i · (√‘-𝐴))) ∉
ℝ+)) |
35 | 33, 34 | syl 17 |
. . . . . . . 8
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
((i · 𝑥) ∉
ℝ+ ↔ (i · (i · (√‘-𝐴))) ∉
ℝ+)) |
36 | 30, 32, 35 | 3anbi123d 1435 |
. . . . . . 7
⊢ (𝑥 = (i ·
(√‘-𝐴)) →
(((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+) ↔ (((i · (√‘-𝐴))↑2) = 𝐴 ∧ 0 ≤ (ℜ‘(i ·
(√‘-𝐴))) ∧
(i · (i · (√‘-𝐴))) ∉
ℝ+))) |
37 | 36 | rspcev 3561 |
. . . . . 6
⊢ (((i
· (√‘-𝐴)) ∈ ℂ ∧ (((i ·
(√‘-𝐴))↑2)
= 𝐴 ∧ 0 ≤
(ℜ‘(i · (√‘-𝐴))) ∧ (i · (i ·
(√‘-𝐴)))
∉ ℝ+)) → ∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉
ℝ+)) |
38 | 21, 28, 37 | syl2anc 584 |
. . . . 5
⊢ ((𝐴 ∈ ℂ ∧
(abs‘𝐴) = -𝐴) → ∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉
ℝ+)) |
39 | 38 | ex 413 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((abs‘𝐴) = -𝐴 → ∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉
ℝ+))) |
40 | 8, 39 | sylbid 239 |
. . 3
⊢ (𝐴 ∈ ℂ →
(((abs‘𝐴) + 𝐴) = 0 → ∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉
ℝ+))) |
41 | | resqrtcl 14965 |
. . . . . . . . 9
⊢
(((abs‘𝐴)
∈ ℝ ∧ 0 ≤ (abs‘𝐴)) → (√‘(abs‘𝐴)) ∈
ℝ) |
42 | 1, 10, 41 | syl2anc 584 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(√‘(abs‘𝐴)) ∈ ℝ) |
43 | 42 | recnd 11003 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(√‘(abs‘𝐴)) ∈ ℂ) |
44 | 43 | adantr 481 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
(√‘(abs‘𝐴)) ∈ ℂ) |
45 | | addcl 10953 |
. . . . . . . . 9
⊢
(((abs‘𝐴)
∈ ℂ ∧ 𝐴
∈ ℂ) → ((abs‘𝐴) + 𝐴) ∈ ℂ) |
46 | 2, 45 | mpancom 685 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
((abs‘𝐴) + 𝐴) ∈
ℂ) |
47 | 46 | adantr 481 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
((abs‘𝐴) + 𝐴) ∈
ℂ) |
48 | | abscl 14990 |
. . . . . . . . . 10
⊢
(((abs‘𝐴) +
𝐴) ∈ ℂ →
(abs‘((abs‘𝐴) +
𝐴)) ∈
ℝ) |
49 | 46, 48 | syl 17 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ →
(abs‘((abs‘𝐴) +
𝐴)) ∈
ℝ) |
50 | 49 | recnd 11003 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(abs‘((abs‘𝐴) +
𝐴)) ∈
ℂ) |
51 | 50 | adantr 481 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
(abs‘((abs‘𝐴) +
𝐴)) ∈
ℂ) |
52 | 46 | abs00ad 15002 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ →
((abs‘((abs‘𝐴)
+ 𝐴)) = 0 ↔
((abs‘𝐴) + 𝐴) = 0)) |
53 | 52 | necon3bid 2988 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
((abs‘((abs‘𝐴)
+ 𝐴)) ≠ 0 ↔
((abs‘𝐴) + 𝐴) ≠ 0)) |
54 | 53 | biimpar 478 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
(abs‘((abs‘𝐴) +
𝐴)) ≠
0) |
55 | 47, 51, 54 | divcld 11751 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
(((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))) ∈ ℂ) |
56 | 44, 55 | mulcld 10995 |
. . . . 5
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) ∈ ℂ) |
57 | | eqid 2738 |
. . . . . 6
⊢
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) = ((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) |
58 | 57 | sqreulem 15071 |
. . . . 5
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) →
((((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))↑2) = 𝐴 ∧ 0 ≤
(ℜ‘((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∧ (i ·
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∉
ℝ+)) |
59 | | oveq1 7282 |
. . . . . . . 8
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → (𝑥↑2) = (((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))↑2)) |
60 | 59 | eqeq1d 2740 |
. . . . . . 7
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → ((𝑥↑2) = 𝐴 ↔ (((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))↑2) = 𝐴)) |
61 | | fveq2 6774 |
. . . . . . . 8
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → (ℜ‘𝑥) =
(ℜ‘((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))))) |
62 | 61 | breq2d 5086 |
. . . . . . 7
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → (0 ≤ (ℜ‘𝑥) ↔ 0 ≤
(ℜ‘((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))))) |
63 | | oveq2 7283 |
. . . . . . . 8
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → (i · 𝑥) = (i ·
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))))) |
64 | | neleq1 3054 |
. . . . . . . 8
⊢ ((i
· 𝑥) = (i ·
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) → ((i · 𝑥) ∉ ℝ+ ↔ (i
· ((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∉
ℝ+)) |
65 | 63, 64 | syl 17 |
. . . . . . 7
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → ((i · 𝑥) ∉ ℝ+ ↔ (i
· ((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∉
ℝ+)) |
66 | 60, 62, 65 | 3anbi123d 1435 |
. . . . . 6
⊢ (𝑥 =
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) → (((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉ ℝ+)
↔ ((((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))↑2) = 𝐴 ∧ 0 ≤
(ℜ‘((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∧ (i ·
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∉
ℝ+))) |
67 | 66 | rspcev 3561 |
. . . . 5
⊢
((((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴)))) ∈ ℂ ∧
((((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))↑2) = 𝐴 ∧ 0 ≤
(ℜ‘((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∧ (i ·
((√‘(abs‘𝐴)) · (((abs‘𝐴) + 𝐴) / (abs‘((abs‘𝐴) + 𝐴))))) ∉ ℝ+)) →
∃𝑥 ∈ ℂ
((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+)) |
68 | 56, 58, 67 | syl2anc 584 |
. . . 4
⊢ ((𝐴 ∈ ℂ ∧
((abs‘𝐴) + 𝐴) ≠ 0) → ∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉
ℝ+)) |
69 | 68 | ex 413 |
. . 3
⊢ (𝐴 ∈ ℂ →
(((abs‘𝐴) + 𝐴) ≠ 0 → ∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉
ℝ+))) |
70 | 40, 69 | pm2.61dne 3031 |
. 2
⊢ (𝐴 ∈ ℂ →
∃𝑥 ∈ ℂ
((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+)) |
71 | | sqrmo 14963 |
. 2
⊢ (𝐴 ∈ ℂ →
∃*𝑥 ∈ ℂ
((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+)) |
72 | | reu5 3361 |
. 2
⊢
(∃!𝑥 ∈
ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+) ↔ (∃𝑥 ∈ ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤ (ℜ‘𝑥) ∧ (i · 𝑥) ∉ ℝ+)
∧ ∃*𝑥 ∈
ℂ ((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+))) |
73 | 70, 71, 72 | sylanbrc 583 |
1
⊢ (𝐴 ∈ ℂ →
∃!𝑥 ∈ ℂ
((𝑥↑2) = 𝐴 ∧ 0 ≤
(ℜ‘𝑥) ∧ (i
· 𝑥) ∉
ℝ+)) |