Proof of Theorem sqrlem12
| Step | Hyp | Ref
| Expression |
| 1 | | sqrlem1.1 |
. . . . . 6
⊢ A
∈ ℝ |
| 2 | | sqrlem1.2 |
. . . . . 6
⊢ 0 < A |
| 3 | | sqrlem12.8 |
. . . . . 6
⊢ S =
{x ∈ ℝ∣(0 ≤ x ∧ (x
· x) ≤ A)} |
| 4 | 1, 2, 3 | sqrlem4 4734 |
. . . . 5
⊢ (D
∈ S ↔ (D ∈ ℝ ∧ (0 ≤ D ∧ (D
· D) ≤ A))) |
| 5 | 4 | pm3.27bd 263 |
. . . 4
⊢ (D
∈ S → (0 ≤ D ∧ (D
· D) ≤ A)) |
| 6 | 5 | pm3.26d 258 |
. . 3
⊢ (D
∈ S → 0 ≤ D) |
| 7 | 4 | pm3.26bd 259 |
. . . 4
⊢ (D
∈ S → D ∈ ℝ) |
| 8 | | ax0re 4063 |
. . . . 5
⊢ 0 ∈ ℝ |
| 9 | | leloet 4284 |
. . . . 5
⊢ ((0 ∈ ℝ ∧ D ∈ ℝ) → (0 ≤ D ↔ (0 < D ∨ 0 = D))) |
| 10 | 8, 9 | mpan 518 |
. . . 4
⊢ (D
∈ ℝ → (0 ≤ D ↔ (0
< D ∨ 0 = D))) |
| 11 | 7, 10 | syl 12 |
. . 3
⊢ (D
∈ S → (0 ≤ D ↔ (0 < D ∨ 0 = D))) |
| 12 | 6, 11 | mpbid 170 |
. 2
⊢ (D
∈ S → (0 < D ∨ 0 = D)) |
| 13 | 5 | pm3.27d 262 |
. . . . . . 7
⊢ (D
∈ S → (D · D)
≤ A) |
| 14 | | sqrlem9.3 |
. . . . . . . . 9
⊢ B
∈ ℝ |
| 15 | | sqrlem9.4 |
. . . . . . . . 9
⊢ C
∈ ℝ |
| 16 | | sqrlem9.5 |
. . . . . . . . 9
⊢ 0 < B |
| 17 | | sqrlem9.6 |
. . . . . . . . 9
⊢ A <
(B · B) |
| 18 | | sqrlem9.7 |
. . . . . . . . 9
⊢ C =
((B + (A / B)) / (1 +
1)) |
| 19 | 1, 2, 14, 15, 16, 17, 18 | sqrlem11 4741 |
. . . . . . . 8
⊢ A <
(C · C) |
| 20 | | axmulrcl 4069 |
. . . . . . . . . 10
⊢ ((D
∈ ℝ ∧ D ∈ ℝ)
→ (D · D) ∈ ℝ) |
| 21 | 20 | anidms 332 |
. . . . . . . . 9
⊢ (D
∈ ℝ → (D · D) ∈ ℝ) |
| 22 | 15, 15 | remulcl 4119 |
. . . . . . . . . . 11
⊢ (C
· C) ∈ ℝ |
| 23 | | lelttrt 4289 |
. . . . . . . . . . 11
⊢ (((D
· D) ∈ ℝ ∧ A ∈ ℝ ∧ (C · C)
∈ ℝ) → (((D ·
D) ≤ A ∧ A <
(C · C)) → (D
· D) < (C · C))) |
| 24 | 22, 23 | mp3an3 641 |
. . . . . . . . . 10
⊢ (((D
· D) ∈ ℝ ∧ A ∈ ℝ) → (((D · D)
≤ A ∧ A < (C
· C)) → (D · D)
< (C · C))) |
| 25 | 1, 24 | mpan2 519 |
. . . . . . . . 9
⊢ ((D
· D) ∈ ℝ →
(((D · D) ≤ A ∧
A < (C · C))
→ (D · D) < (C
· C))) |
| 26 | 7, 21, 25 | 3syl 21 |
. . . . . . . 8
⊢ (D
∈ S → (((D · D)
≤ A ∧ A < (C
· C)) → (D · D)
< (C · C))) |
| 27 | 19, 26 | mpan2i 522 |
. . . . . . 7
⊢ (D
∈ S → ((D · D)
≤ A → (D · D)
< (C · C))) |
| 28 | 13, 27 | mpd 46 |
. . . . . 6
⊢ (D
∈ S → (D · D)
< (C · C)) |
| 29 | 28 | adantr 306 |
. . . . 5
⊢ ((D
∈ S ∧ 0 < D) → (D
· D) < (C · C)) |
| 30 | 1, 2, 14, 15, 16, 17, 18 | sqrlem9 4739 |
. . . . . . 7
⊢ 0 < C |
| 31 | | breq2 2066 |
. . . . . . . . . . 11
⊢ (D =
if(D ∈ ℝ, D, 0) → (0 < D ↔ 0 < if(D ∈ ℝ, D, 0))) |
| 32 | 31 | anbi1d 469 |
. . . . . . . . . 10
⊢ (D =
if(D ∈ ℝ, D, 0) → ((0 < D ∧ 0 < C) ↔ (0 < if(D ∈ ℝ, D, 0) ∧ 0 < C))) |
| 33 | | breq1 2065 |
. . . . . . . . . . 11
⊢ (D =
if(D ∈ ℝ, D, 0) → (D
< C ↔ if(D ∈ ℝ, D, 0) < C)) |
| 34 | | opreq12 3008 |
. . . . . . . . . . . . 13
⊢ ((D =
if(D ∈ ℝ, D, 0) ∧ D =
if(D ∈ ℝ, D, 0)) → (D
· D) = (if(D ∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0))) |
| 35 | 34 | anidms 332 |
. . . . . . . . . . . 12
⊢ (D =
if(D ∈ ℝ, D, 0) → (D
· D) = (if(D ∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0))) |
| 36 | 35 | breq1d 2071 |
. . . . . . . . . . 11
⊢ (D =
if(D ∈ ℝ, D, 0) → ((D
· D) < (C · C)
↔ (if(D ∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0)) < (C
· C))) |
| 37 | 33, 36 | bibi12d 477 |
. . . . . . . . . 10
⊢ (D =
if(D ∈ ℝ, D, 0) → ((D
< C ↔ (D · D)
< (C · C)) ↔ (if(D
∈ ℝ, D, 0) < C ↔ (if(D
∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0)) < (C
· C)))) |
| 38 | 32, 37 | imbi12d 474 |
. . . . . . . . 9
⊢ (D =
if(D ∈ ℝ, D, 0) → (((0 < D ∧ 0 < C) → (D
< C ↔ (D · D)
< (C · C))) ↔ ((0 < if(D ∈ ℝ, D, 0) ∧ 0 < C) → (if(D
∈ ℝ, D, 0) < C ↔ (if(D
∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0)) < (C
· C))))) |
| 39 | 8 | elimel 1793 |
. . . . . . . . . . 11
⊢ if(D
∈ ℝ, D, 0) ∈
ℝ |
| 40 | 39, 15 | lt2sq 4414 |
. . . . . . . . . 10
⊢ ((0 ≤ if(D ∈ ℝ, D, 0) ∧ 0 ≤ C) → (if(D
∈ ℝ, D, 0) < C ↔ (if(D
∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0)) < (C
· C))) |
| 41 | 8, 39 | ltle 4302 |
. . . . . . . . . 10
⊢ (0 < if(D ∈ ℝ, D, 0) → 0 ≤ if(D ∈ ℝ, D, 0)) |
| 42 | 8, 15 | ltle 4302 |
. . . . . . . . . 10
⊢ (0 < C → 0 ≤ C) |
| 43 | 40, 41, 42 | syl2an 349 |
. . . . . . . . 9
⊢ ((0 < if(D ∈ ℝ, D, 0) ∧ 0 < C) → (if(D
∈ ℝ, D, 0) < C ↔ (if(D
∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0)) < (C
· C))) |
| 44 | 38, 43 | dedth 1784 |
. . . . . . . 8
⊢ (D
∈ ℝ → ((0 < D ∧ 0
< C) → (D < C ↔
(D · D) < (C
· C)))) |
| 45 | 7, 44 | syl 12 |
. . . . . . 7
⊢ (D
∈ S → ((0 < D ∧ 0 < C) → (D
< C ↔ (D · D)
< (C · C)))) |
| 46 | 30, 45 | mpan2i 522 |
. . . . . 6
⊢ (D
∈ S → (0 < D → (D <
C ↔ (D · D)
< (C · C)))) |
| 47 | 46 | imp 277 |
. . . . 5
⊢ ((D
∈ S ∧ 0 < D) → (D
< C ↔ (D · D)
< (C · C))) |
| 48 | 29, 47 | mpbird 171 |
. . . 4
⊢ ((D
∈ S ∧ 0 < D) → D <
C) |
| 49 | 48 | exp 291 |
. . 3
⊢ (D
∈ S → (0 < D → D <
C)) |
| 50 | | breq1 2065 |
. . . . 5
⊢ (0 = D
→ (0 < C ↔ D < C)) |
| 51 | 30, 50 | mpbii 168 |
. . . 4
⊢ (0 = D
→ D < C) |
| 52 | 51 | a1i 7 |
. . 3
⊢ (D
∈ S → (0 = D → D <
C)) |
| 53 | 49, 52 | jaod 329 |
. 2
⊢ (D
∈ S → ((0 < D ∨ 0 = D)
→ D < C)) |
| 54 | 12, 53 | mpd 46 |
1
⊢ (D
∈ S → D < C) |