Proof of Theorem iccneg
| Step | Hyp | Ref
| Expression |
| 1 | | renegcl 8304 |
. . . . 5
⊢ (𝐶 ∈ ℝ → -𝐶 ∈
ℝ) |
| 2 | | ax-1 6 |
. . . . 5
⊢ (𝐶 ∈ ℝ → (-𝐶 ∈ ℝ → 𝐶 ∈
ℝ)) |
| 3 | 1, 2 | impbid2 143 |
. . . 4
⊢ (𝐶 ∈ ℝ → (𝐶 ∈ ℝ ↔ -𝐶 ∈
ℝ)) |
| 4 | 3 | 3ad2ant3 1022 |
. . 3
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐶 ∈ ℝ ↔ -𝐶 ∈
ℝ)) |
| 5 | | ancom 266 |
. . . 4
⊢ ((𝐶 ≤ 𝐵 ∧ 𝐴 ≤ 𝐶) ↔ (𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵)) |
| 6 | | leneg 8509 |
. . . . . . 7
⊢ ((𝐶 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐶 ≤ 𝐵 ↔ -𝐵 ≤ -𝐶)) |
| 7 | 6 | ancoms 268 |
. . . . . 6
⊢ ((𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐶 ≤ 𝐵 ↔ -𝐵 ≤ -𝐶)) |
| 8 | 7 | 3adant1 1017 |
. . . . 5
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐶 ≤ 𝐵 ↔ -𝐵 ≤ -𝐶)) |
| 9 | | leneg 8509 |
. . . . . 6
⊢ ((𝐴 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐴 ≤ 𝐶 ↔ -𝐶 ≤ -𝐴)) |
| 10 | 9 | 3adant2 1018 |
. . . . 5
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐴 ≤ 𝐶 ↔ -𝐶 ≤ -𝐴)) |
| 11 | 8, 10 | anbi12d 473 |
. . . 4
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐶 ≤ 𝐵 ∧ 𝐴 ≤ 𝐶) ↔ (-𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴))) |
| 12 | 5, 11 | bitr3id 194 |
. . 3
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵) ↔ (-𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴))) |
| 13 | 4, 12 | anbi12d 473 |
. 2
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐶 ∈ ℝ ∧ (𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵)) ↔ (-𝐶 ∈ ℝ ∧ (-𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴)))) |
| 14 | | elicc2 10030 |
. . . 4
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐶 ∈ (𝐴[,]𝐵) ↔ (𝐶 ∈ ℝ ∧ 𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵))) |
| 15 | 14 | 3adant3 1019 |
. . 3
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐶 ∈ (𝐴[,]𝐵) ↔ (𝐶 ∈ ℝ ∧ 𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵))) |
| 16 | | 3anass 984 |
. . 3
⊢ ((𝐶 ∈ ℝ ∧ 𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵) ↔ (𝐶 ∈ ℝ ∧ (𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵))) |
| 17 | 15, 16 | bitrdi 196 |
. 2
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐶 ∈ (𝐴[,]𝐵) ↔ (𝐶 ∈ ℝ ∧ (𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵)))) |
| 18 | | renegcl 8304 |
. . . . 5
⊢ (𝐵 ∈ ℝ → -𝐵 ∈
ℝ) |
| 19 | | renegcl 8304 |
. . . . 5
⊢ (𝐴 ∈ ℝ → -𝐴 ∈
ℝ) |
| 20 | | elicc2 10030 |
. . . . 5
⊢ ((-𝐵 ∈ ℝ ∧ -𝐴 ∈ ℝ) → (-𝐶 ∈ (-𝐵[,]-𝐴) ↔ (-𝐶 ∈ ℝ ∧ -𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴))) |
| 21 | 18, 19, 20 | syl2anr 290 |
. . . 4
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (-𝐶 ∈ (-𝐵[,]-𝐴) ↔ (-𝐶 ∈ ℝ ∧ -𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴))) |
| 22 | 21 | 3adant3 1019 |
. . 3
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (-𝐶 ∈ (-𝐵[,]-𝐴) ↔ (-𝐶 ∈ ℝ ∧ -𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴))) |
| 23 | | 3anass 984 |
. . 3
⊢ ((-𝐶 ∈ ℝ ∧ -𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴) ↔ (-𝐶 ∈ ℝ ∧ (-𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴))) |
| 24 | 22, 23 | bitrdi 196 |
. 2
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (-𝐶 ∈ (-𝐵[,]-𝐴) ↔ (-𝐶 ∈ ℝ ∧ (-𝐵 ≤ -𝐶 ∧ -𝐶 ≤ -𝐴)))) |
| 25 | 13, 17, 24 | 3bitr4d 220 |
1
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐶 ∈ (𝐴[,]𝐵) ↔ -𝐶 ∈ (-𝐵[,]-𝐴))) |