Proof of Theorem ex-fl
| Step | Hyp | Ref
| Expression |
| 1 | | 1re 8042 |
. . . 4
⊢ 1 ∈
ℝ |
| 2 | | 3re 9081 |
. . . . 5
⊢ 3 ∈
ℝ |
| 3 | 2 | rehalfcli 9257 |
. . . 4
⊢ (3 / 2)
∈ ℝ |
| 4 | | 2cn 9078 |
. . . . . . 7
⊢ 2 ∈
ℂ |
| 5 | 4 | mullidi 8046 |
. . . . . 6
⊢ (1
· 2) = 2 |
| 6 | | 2lt3 9178 |
. . . . . 6
⊢ 2 <
3 |
| 7 | 5, 6 | eqbrtri 4055 |
. . . . 5
⊢ (1
· 2) < 3 |
| 8 | | 2pos 9098 |
. . . . . 6
⊢ 0 <
2 |
| 9 | | 2re 9077 |
. . . . . . 7
⊢ 2 ∈
ℝ |
| 10 | 1, 2, 9 | ltmuldivi 8966 |
. . . . . 6
⊢ (0 < 2
→ ((1 · 2) < 3 ↔ 1 < (3 / 2))) |
| 11 | 8, 10 | ax-mp 5 |
. . . . 5
⊢ ((1
· 2) < 3 ↔ 1 < (3 / 2)) |
| 12 | 7, 11 | mpbi 145 |
. . . 4
⊢ 1 < (3
/ 2) |
| 13 | 1, 3, 12 | ltleii 8146 |
. . 3
⊢ 1 ≤ (3
/ 2) |
| 14 | | 3lt4 9180 |
. . . . . 6
⊢ 3 <
4 |
| 15 | | 2t2e4 9162 |
. . . . . 6
⊢ (2
· 2) = 4 |
| 16 | 14, 15 | breqtrri 4061 |
. . . . 5
⊢ 3 < (2
· 2) |
| 17 | 9, 8 | pm3.2i 272 |
. . . . . 6
⊢ (2 ∈
ℝ ∧ 0 < 2) |
| 18 | | ltdivmul 8920 |
. . . . . 6
⊢ ((3
∈ ℝ ∧ 2 ∈ ℝ ∧ (2 ∈ ℝ ∧ 0 < 2))
→ ((3 / 2) < 2 ↔ 3 < (2 · 2))) |
| 19 | 2, 9, 17, 18 | mp3an 1348 |
. . . . 5
⊢ ((3 / 2)
< 2 ↔ 3 < (2 · 2)) |
| 20 | 16, 19 | mpbir 146 |
. . . 4
⊢ (3 / 2)
< 2 |
| 21 | | df-2 9066 |
. . . 4
⊢ 2 = (1 +
1) |
| 22 | 20, 21 | breqtri 4059 |
. . 3
⊢ (3 / 2)
< (1 + 1) |
| 23 | | 3z 9372 |
. . . . 5
⊢ 3 ∈
ℤ |
| 24 | | 2nn 9169 |
. . . . 5
⊢ 2 ∈
ℕ |
| 25 | | znq 9715 |
. . . . 5
⊢ ((3
∈ ℤ ∧ 2 ∈ ℕ) → (3 / 2) ∈
ℚ) |
| 26 | 23, 24, 25 | mp2an 426 |
. . . 4
⊢ (3 / 2)
∈ ℚ |
| 27 | | 1z 9369 |
. . . 4
⊢ 1 ∈
ℤ |
| 28 | | flqbi 10397 |
. . . 4
⊢ (((3 / 2)
∈ ℚ ∧ 1 ∈ ℤ) → ((⌊‘(3 / 2)) = 1
↔ (1 ≤ (3 / 2) ∧ (3 / 2) < (1 + 1)))) |
| 29 | 26, 27, 28 | mp2an 426 |
. . 3
⊢
((⌊‘(3 / 2)) = 1 ↔ (1 ≤ (3 / 2) ∧ (3 / 2) <
(1 + 1))) |
| 30 | 13, 22, 29 | mpbir2an 944 |
. 2
⊢
(⌊‘(3 / 2)) = 1 |
| 31 | 9 | renegcli 8305 |
. . . 4
⊢ -2 ∈
ℝ |
| 32 | 3 | renegcli 8305 |
. . . 4
⊢ -(3 / 2)
∈ ℝ |
| 33 | 3, 9 | ltnegi 8537 |
. . . . 5
⊢ ((3 / 2)
< 2 ↔ -2 < -(3 / 2)) |
| 34 | 20, 33 | mpbi 145 |
. . . 4
⊢ -2 <
-(3 / 2) |
| 35 | 31, 32, 34 | ltleii 8146 |
. . 3
⊢ -2 ≤
-(3 / 2) |
| 36 | 4 | negcli 8311 |
. . . . . . 7
⊢ -2 ∈
ℂ |
| 37 | | ax-1cn 7989 |
. . . . . . 7
⊢ 1 ∈
ℂ |
| 38 | | negdi2 8301 |
. . . . . . 7
⊢ ((-2
∈ ℂ ∧ 1 ∈ ℂ) → -(-2 + 1) = (--2 −
1)) |
| 39 | 36, 37, 38 | mp2an 426 |
. . . . . 6
⊢ -(-2 + 1)
= (--2 − 1) |
| 40 | 4 | negnegi 8313 |
. . . . . . 7
⊢ --2 =
2 |
| 41 | 40 | oveq1i 5935 |
. . . . . 6
⊢ (--2
− 1) = (2 − 1) |
| 42 | 39, 41 | eqtri 2217 |
. . . . 5
⊢ -(-2 + 1)
= (2 − 1) |
| 43 | | 2m1e1 9125 |
. . . . . 6
⊢ (2
− 1) = 1 |
| 44 | 43, 12 | eqbrtri 4055 |
. . . . 5
⊢ (2
− 1) < (3 / 2) |
| 45 | 42, 44 | eqbrtri 4055 |
. . . 4
⊢ -(-2 + 1)
< (3 / 2) |
| 46 | 31, 1 | readdcli 8056 |
. . . . 5
⊢ (-2 + 1)
∈ ℝ |
| 47 | 46, 3 | ltnegcon1i 8543 |
. . . 4
⊢ (-(-2 +
1) < (3 / 2) ↔ -(3 / 2) < (-2 + 1)) |
| 48 | 45, 47 | mpbi 145 |
. . 3
⊢ -(3 / 2)
< (-2 + 1) |
| 49 | | qnegcl 9727 |
. . . . 5
⊢ ((3 / 2)
∈ ℚ → -(3 / 2) ∈ ℚ) |
| 50 | 26, 49 | ax-mp 5 |
. . . 4
⊢ -(3 / 2)
∈ ℚ |
| 51 | | 2z 9371 |
. . . . 5
⊢ 2 ∈
ℤ |
| 52 | | znegcl 9374 |
. . . . 5
⊢ (2 ∈
ℤ → -2 ∈ ℤ) |
| 53 | 51, 52 | ax-mp 5 |
. . . 4
⊢ -2 ∈
ℤ |
| 54 | | flqbi 10397 |
. . . 4
⊢ ((-(3 /
2) ∈ ℚ ∧ -2 ∈ ℤ) → ((⌊‘-(3 / 2)) =
-2 ↔ (-2 ≤ -(3 / 2) ∧ -(3 / 2) < (-2 + 1)))) |
| 55 | 50, 53, 54 | mp2an 426 |
. . 3
⊢
((⌊‘-(3 / 2)) = -2 ↔ (-2 ≤ -(3 / 2) ∧ -(3 / 2)
< (-2 + 1))) |
| 56 | 35, 48, 55 | mpbir2an 944 |
. 2
⊢
(⌊‘-(3 / 2)) = -2 |
| 57 | 30, 56 | pm3.2i 272 |
1
⊢
((⌊‘(3 / 2)) = 1 ∧ (⌊‘-(3 / 2)) =
-2) |