Proof of Theorem ltdiv23t
| Step | Hyp | Ref
| Expression |
| 1 | | opreq1 3006 |
. . . . 5
⊢ (A =
if(A ∈ ℝ, A, 0) → (A
/ B) = (if(A ∈ ℝ, A, 0) / B)) |
| 2 | 1 | breq1d 2071 |
. . . 4
⊢ (A =
if(A ∈ ℝ, A, 0) → ((A
/ B) < C ↔ (if(A
∈ ℝ, A, 0) / B) < C)) |
| 3 | | opreq1 3006 |
. . . . 5
⊢ (A =
if(A ∈ ℝ, A, 0) → (A
/ C) = (if(A ∈ ℝ, A, 0) / C)) |
| 4 | 3 | breq1d 2071 |
. . . 4
⊢ (A =
if(A ∈ ℝ, A, 0) → ((A
/ C) < B ↔ (if(A
∈ ℝ, A, 0) / C) < B)) |
| 5 | 2, 4 | bibi12d 477 |
. . 3
⊢ (A =
if(A ∈ ℝ, A, 0) → (((A / B) <
C ↔ (A / C) <
B) ↔ ((if(A ∈ ℝ, A, 0) / B) <
C ↔ (if(A ∈ ℝ, A, 0) / C) <
B))) |
| 6 | 5 | imbi2d 464 |
. 2
⊢ (A =
if(A ∈ ℝ, A, 0) → (((0 < B ∧ 0 < C) → ((A /
B) < C ↔ (A /
C) < B)) ↔ ((0 < B ∧ 0 < C) → ((if(A
∈ ℝ, A, 0) / B) < C ↔
(if(A ∈ ℝ, A, 0) / C) <
B)))) |
| 7 | | breq2 2066 |
. . . 4
⊢ (B =
if(B ∈ ℝ, B, 0) → (0 < B ↔ 0 < if(B ∈ ℝ, B, 0))) |
| 8 | 7 | anbi1d 469 |
. . 3
⊢ (B =
if(B ∈ ℝ, B, 0) → ((0 < B ∧ 0 < C) ↔ (0 < if(B ∈ ℝ, B, 0) ∧ 0 < C))) |
| 9 | | opreq2 3007 |
. . . . 5
⊢ (B =
if(B ∈ ℝ, B, 0) → (if(A ∈ ℝ, A, 0) / B) =
(if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0))) |
| 10 | 9 | breq1d 2071 |
. . . 4
⊢ (B =
if(B ∈ ℝ, B, 0) → ((if(A ∈ ℝ, A, 0) / B) <
C ↔ (if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < C)) |
| 11 | | breq2 2066 |
. . . 4
⊢ (B =
if(B ∈ ℝ, B, 0) → ((if(A ∈ ℝ, A, 0) / C) <
B ↔ (if(A ∈ ℝ, A, 0) / C) <
if(B ∈ ℝ, B, 0))) |
| 12 | 10, 11 | bibi12d 477 |
. . 3
⊢ (B =
if(B ∈ ℝ, B, 0) → (((if(A ∈ ℝ, A, 0) / B) <
C ↔ (if(A ∈ ℝ, A, 0) / C) <
B) ↔ ((if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < C ↔ (if(A
∈ ℝ, A, 0) / C) < if(B
∈ ℝ, B, 0)))) |
| 13 | 8, 12 | imbi12d 474 |
. 2
⊢ (B =
if(B ∈ ℝ, B, 0) → (((0 < B ∧ 0 < C) → ((if(A
∈ ℝ, A, 0) / B) < C ↔
(if(A ∈ ℝ, A, 0) / C) <
B)) ↔ ((0 < if(B ∈ ℝ, B, 0) ∧ 0 < C) → ((if(A
∈ ℝ, A, 0) / if(B ∈ ℝ, B, 0)) < C
↔ (if(A ∈ ℝ, A, 0) / C) <
if(B ∈ ℝ, B, 0))))) |
| 14 | | breq2 2066 |
. . . 4
⊢ (C =
if(C ∈ ℝ, C, 0) → (0 < C ↔ 0 < if(C ∈ ℝ, C, 0))) |
| 15 | 14 | anbi2d 468 |
. . 3
⊢ (C =
if(C ∈ ℝ, C, 0) → ((0 < if(B ∈ ℝ, B, 0) ∧ 0 < C) ↔ (0 < if(B ∈ ℝ, B, 0) ∧ 0 < if(C ∈ ℝ, C, 0)))) |
| 16 | | breq2 2066 |
. . . 4
⊢ (C =
if(C ∈ ℝ, C, 0) → ((if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < C ↔ (if(A
∈ ℝ, A, 0) / if(B ∈ ℝ, B, 0)) < if(C
∈ ℝ, C, 0))) |
| 17 | | opreq2 3007 |
. . . . 5
⊢ (C =
if(C ∈ ℝ, C, 0) → (if(A ∈ ℝ, A, 0) / C) =
(if(A ∈ ℝ, A, 0) / if(C
∈ ℝ, C, 0))) |
| 18 | 17 | breq1d 2071 |
. . . 4
⊢ (C =
if(C ∈ ℝ, C, 0) → ((if(A ∈ ℝ, A, 0) / C) <
if(B ∈ ℝ, B, 0) ↔ (if(A ∈ ℝ, A, 0) / if(C
∈ ℝ, C, 0)) < if(B ∈ ℝ, B, 0))) |
| 19 | 16, 18 | bibi12d 477 |
. . 3
⊢ (C =
if(C ∈ ℝ, C, 0) → (((if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < C ↔ (if(A
∈ ℝ, A, 0) / C) < if(B
∈ ℝ, B, 0)) ↔ ((if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < if(C ∈ ℝ, C, 0) ↔ (if(A ∈ ℝ, A, 0) / if(C
∈ ℝ, C, 0)) < if(B ∈ ℝ, B, 0)))) |
| 20 | 15, 19 | imbi12d 474 |
. 2
⊢ (C =
if(C ∈ ℝ, C, 0) → (((0 < if(B ∈ ℝ, B, 0) ∧ 0 < C) → ((if(A
∈ ℝ, A, 0) / if(B ∈ ℝ, B, 0)) < C
↔ (if(A ∈ ℝ, A, 0) / C) <
if(B ∈ ℝ, B, 0))) ↔ ((0 < if(B ∈ ℝ, B, 0) ∧ 0 < if(C ∈ ℝ, C, 0)) → ((if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < if(C ∈ ℝ, C, 0) ↔ (if(A ∈ ℝ, A, 0) / if(C
∈ ℝ, C, 0)) < if(B ∈ ℝ, B, 0))))) |
| 21 | | ax0re 4063 |
. . . 4
⊢ 0 ∈ ℝ |
| 22 | 21 | elimel 1793 |
. . 3
⊢ if(A
∈ ℝ, A, 0) ∈
ℝ |
| 23 | 21 | elimel 1793 |
. . 3
⊢ if(B
∈ ℝ, B, 0) ∈
ℝ |
| 24 | 21 | elimel 1793 |
. . 3
⊢ if(C
∈ ℝ, C, 0) ∈
ℝ |
| 25 | 22, 23, 24 | ltdiv23 4413 |
. 2
⊢ ((0 < if(B ∈ ℝ, B, 0) ∧ 0 < if(C ∈ ℝ, C, 0)) → ((if(A ∈ ℝ, A, 0) / if(B
∈ ℝ, B, 0)) < if(C ∈ ℝ, C, 0) ↔ (if(A ∈ ℝ, A, 0) / if(C
∈ ℝ, C, 0)) < if(B ∈ ℝ, B, 0))) |
| 26 | 6, 13, 20, 25 | dedth3h 1788 |
1
⊢ ((A
∈ ℝ ∧ B ∈ ℝ ∧
C ∈ ℝ) → ((0 < B ∧ 0 < C) → ((A /
B) < C ↔ (A /
C) < B))) |