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 6690 |
. . . . 5
⊢ (D ∈ S ↔ (D
∈ ℝ ⋀ (0 ≤ D
⋀ (D
· D) ≤ A))) |
| 5 | 4 | pm3.27bi 326 |
. . . 4
⊢ (D ∈ S → (0 ≤ D ⋀ (D · D)
≤ A)) |
| 6 | 5 | pm3.26d 321 |
. . 3
⊢ (D ∈ S → 0 ≤ D) |
| 7 | 4 | pm3.26bi 322 |
. . . 4
⊢ (D ∈ S → D ∈ ℝ) |
| 8 | | 0re 5453 |
. . . . 5
⊢ 0 ∈ ℝ |
| 9 | | leloet 5531 |
. . . . 5
⊢ ((0 ∈ ℝ ⋀ D ∈ ℝ) → (0
≤ D ↔ (0 < D ⋁ 0 = D))) |
| 10 | 8, 9 | mpan 699 |
. . . 4
⊢ (D ∈ ℝ → (0 ≤ D ↔ (0 < D ⋁ 0 = D))) |
| 11 | 7, 10 | syl 10 |
. . 3
⊢ (D ∈ S → (0 ≤ D ↔ (0 < D ⋁ 0 = D))) |
| 12 | 6, 11 | mpbid 195 |
. 2
⊢ (D ∈ S → (0 < D ⋁ 0 = D)) |
| 13 | 5 | pm3.27d 325 |
. . . . . . 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 6697 |
. . . . . . . 8
⊢ A < (C
· C) |
| 20 | | axmulrcl 5287 |
. . . . . . . . . 10
⊢ ((D ∈ ℝ ⋀ D ∈ ℝ) → (D
· D) ∈ ℝ) |
| 21 | 20 | anidms 437 |
. . . . . . . . 9
⊢ (D ∈ ℝ → (D
· D) ∈ ℝ) |
| 22 | 15, 15 | remulcl 5348 |
. . . . . . . . . 10
⊢ (C · C)
∈ ℝ |
| 23 | | lelttrt 5536 |
. . . . . . . . . 10
⊢ (((D · D)
∈ ℝ ⋀ A ∈ ℝ ⋀ (C ·
C) ∈
ℝ) → (((D · D)
≤ A ⋀
A < (C · C))
→ (D · D) < (C
· C))) |
| 24 | 1, 22, 23 | mp3an23 912 |
. . . . . . . . 9
⊢ ((D · D)
∈ ℝ →
(((D · D) ≤ A ⋀ A <
(C · C)) → (D
· D) < (C · C))) |
| 25 | 7, 21, 24 | 3syl 20 |
. . . . . . . 8
⊢ (D ∈ S → (((D
· D) ≤ A ⋀ A < (C
· C)) → (D · D)
< (C · C))) |
| 26 | 19, 25 | mpan2i 703 |
. . . . . . 7
⊢ (D ∈ S → ((D
· D) ≤ A → (D
· D) < (C · C))) |
| 27 | 13, 26 | mpd 26 |
. . . . . 6
⊢ (D ∈ S → (D
· D) < (C · C)) |
| 28 | 27 | adantr 391 |
. . . . 5
⊢ ((D ∈ S ⋀ 0 <
D) → (D · D)
< (C · C)) |
| 29 | 1, 2, 14, 15, 16, 17, 18 | sqrlem9 6695 |
. . . . . . 7
⊢ 0 < C |
| 30 | | breq2 2636 |
. . . . . . . . . . 11
⊢ (D = if(D ∈ ℝ, D, 0) → (0 < D ↔ 0 < if(D ∈ ℝ, D,
0))) |
| 31 | 30 | anbi1d 620 |
. . . . . . . . . 10
⊢ (D = if(D ∈ ℝ, D, 0) → ((0 < D ⋀ 0 <
C) ↔ (0 < if(D ∈ ℝ, D, 0) ⋀ 0 < C))) |
| 32 | | breq1 2635 |
. . . . . . . . . . 11
⊢ (D = if(D ∈ ℝ, D, 0) → (D
< C ↔ if(D ∈ ℝ, D, 0) <
C)) |
| 33 | | opreq12 3984 |
. . . . . . . . . . . . 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))) |
| 34 | 33 | anidms 437 |
. . . . . . . . . . . 12
⊢ (D = if(D ∈ ℝ, D, 0) → (D
· D) = ( if(D ∈ ℝ, D, 0)
· if(D ∈ ℝ, D, 0))) |
| 35 | 34 | breq1d 2642 |
. . . . . . . . . . 11
⊢ (D = if(D ∈ ℝ, D, 0) → ((D
· D) < (C · C)
↔ ( if(D ∈ ℝ, D, 0) · if(D ∈ ℝ, D, 0)) <
(C · C))) |
| 36 | 32, 35 | bibi12d 632 |
. . . . . . . . . 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)))) |
| 37 | 31, 36 | imbi12d 629 |
. . . . . . . . 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))))) |
| 38 | 8 | elimel 2404 |
. . . . . . . . . . 11
⊢ if(D ∈ ℝ, D, 0) ∈ ℝ |
| 39 | 38, 15 | lt2msq 5887 |
. . . . . . . . . 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))) |
| 40 | 8, 38 | ltle 5593 |
. . . . . . . . . 10
⊢ (0 < if(D ∈ ℝ, D, 0)
→ 0 ≤ if(D ∈ ℝ, D, 0)) |
| 41 | 8, 15 | ltle 5593 |
. . . . . . . . . 10
⊢ (0 < C → 0 ≤ C) |
| 42 | 39, 40, 41 | syl2an 457 |
. . . . . . . . 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))) |
| 43 | 37, 42 | dedth 2393 |
. . . . . . . 8
⊢ (D ∈ ℝ → ((0 < D ⋀ 0 <
C) → (D < C ↔
(D · D) < (C
· C)))) |
| 44 | 7, 43 | syl 10 |
. . . . . . 7
⊢ (D ∈ S → ((0 < D ⋀ 0 <
C) → (D < C ↔
(D · D) < (C
· C)))) |
| 45 | 29, 44 | mpan2i 703 |
. . . . . 6
⊢ (D ∈ S → (0 < D → (D <
C ↔ (D · D)
< (C · C)))) |
| 46 | 45 | imp 350 |
. . . . 5
⊢ ((D ∈ S ⋀ 0 <
D) → (D < C ↔
(D · D) < (C
· C))) |
| 47 | 28, 46 | mpbird 196 |
. . . 4
⊢ ((D ∈ S ⋀ 0 <
D) → D < C) |
| 48 | 47 | ex 373 |
. . 3
⊢ (D ∈ S → (0 < D → D <
C)) |
| 49 | | breq1 2635 |
. . . . 5
⊢ (0 = D → (0 < C ↔ D <
C)) |
| 50 | 29, 49 | mpbii 193 |
. . . 4
⊢ (0 = D → D <
C) |
| 51 | 50 | a1i 8 |
. . 3
⊢ (D ∈ S → (0 = D
→ D < C)) |
| 52 | 48, 51 | jaod 426 |
. 2
⊢ (D ∈ S → ((0 < D ⋁ 0 = D) → D <
C)) |
| 53 | 12, 52 | mpd 26 |
1
⊢ (D ∈ S → D <
C) |