Proof of Theorem xrlttri3
Step | Hyp | Ref
| Expression |
1 | | elxr 9712 |
. 2
⊢ (𝐴 ∈ ℝ*
↔ (𝐴 ∈ ℝ
∨ 𝐴 = +∞ ∨
𝐴 =
-∞)) |
2 | | elxr 9712 |
. 2
⊢ (𝐵 ∈ ℝ*
↔ (𝐵 ∈ ℝ
∨ 𝐵 = +∞ ∨
𝐵 =
-∞)) |
3 | | lttri3 7978 |
. . . . . 6
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
4 | 3 | ancoms 266 |
. . . . 5
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
5 | | renepnf 7946 |
. . . . . . . . . 10
⊢ (𝐵 ∈ ℝ → 𝐵 ≠ +∞) |
6 | 5 | adantr 274 |
. . . . . . . . 9
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → 𝐵 ≠ +∞) |
7 | | neeq2 2350 |
. . . . . . . . . 10
⊢ (𝐴 = +∞ → (𝐵 ≠ 𝐴 ↔ 𝐵 ≠ +∞)) |
8 | 7 | adantl 275 |
. . . . . . . . 9
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → (𝐵 ≠ 𝐴 ↔ 𝐵 ≠ +∞)) |
9 | 6, 8 | mpbird 166 |
. . . . . . . 8
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → 𝐵 ≠ 𝐴) |
10 | 9 | necomd 2422 |
. . . . . . 7
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → 𝐴 ≠ 𝐵) |
11 | 10 | neneqd 2357 |
. . . . . 6
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → ¬ 𝐴 = 𝐵) |
12 | | ltpnf 9716 |
. . . . . . . . 9
⊢ (𝐵 ∈ ℝ → 𝐵 < +∞) |
13 | 12 | adantr 274 |
. . . . . . . 8
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → 𝐵 < +∞) |
14 | | breq2 3986 |
. . . . . . . . 9
⊢ (𝐴 = +∞ → (𝐵 < 𝐴 ↔ 𝐵 < +∞)) |
15 | 14 | adantl 275 |
. . . . . . . 8
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → (𝐵 < 𝐴 ↔ 𝐵 < +∞)) |
16 | 13, 15 | mpbird 166 |
. . . . . . 7
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → 𝐵 < 𝐴) |
17 | | notnot 619 |
. . . . . . . . 9
⊢ ((𝐴 < 𝐵 ∨ 𝐵 < 𝐴) → ¬ ¬ (𝐴 < 𝐵 ∨ 𝐵 < 𝐴)) |
18 | 17 | olcs 726 |
. . . . . . . 8
⊢ (𝐵 < 𝐴 → ¬ ¬ (𝐴 < 𝐵 ∨ 𝐵 < 𝐴)) |
19 | | ioran 742 |
. . . . . . . 8
⊢ (¬
(𝐴 < 𝐵 ∨ 𝐵 < 𝐴) ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
20 | 18, 19 | sylnib 666 |
. . . . . . 7
⊢ (𝐵 < 𝐴 → ¬ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
21 | 16, 20 | syl 14 |
. . . . . 6
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → ¬ (¬
𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
22 | 11, 21 | 2falsed 692 |
. . . . 5
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = +∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
23 | | renemnf 7947 |
. . . . . . . . . 10
⊢ (𝐵 ∈ ℝ → 𝐵 ≠ -∞) |
24 | 23 | adantr 274 |
. . . . . . . . 9
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → 𝐵 ≠ -∞) |
25 | | neeq2 2350 |
. . . . . . . . . 10
⊢ (𝐴 = -∞ → (𝐵 ≠ 𝐴 ↔ 𝐵 ≠ -∞)) |
26 | 25 | adantl 275 |
. . . . . . . . 9
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → (𝐵 ≠ 𝐴 ↔ 𝐵 ≠ -∞)) |
27 | 24, 26 | mpbird 166 |
. . . . . . . 8
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → 𝐵 ≠ 𝐴) |
28 | 27 | necomd 2422 |
. . . . . . 7
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → 𝐴 ≠ 𝐵) |
29 | 28 | neneqd 2357 |
. . . . . 6
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → ¬ 𝐴 = 𝐵) |
30 | | mnflt 9719 |
. . . . . . . . 9
⊢ (𝐵 ∈ ℝ → -∞
< 𝐵) |
31 | 30 | adantr 274 |
. . . . . . . 8
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → -∞
< 𝐵) |
32 | | breq1 3985 |
. . . . . . . . 9
⊢ (𝐴 = -∞ → (𝐴 < 𝐵 ↔ -∞ < 𝐵)) |
33 | 32 | adantl 275 |
. . . . . . . 8
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → (𝐴 < 𝐵 ↔ -∞ < 𝐵)) |
34 | 31, 33 | mpbird 166 |
. . . . . . 7
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → 𝐴 < 𝐵) |
35 | | orc 702 |
. . . . . . 7
⊢ (𝐴 < 𝐵 → (𝐴 < 𝐵 ∨ 𝐵 < 𝐴)) |
36 | | oranim 771 |
. . . . . . 7
⊢ ((𝐴 < 𝐵 ∨ 𝐵 < 𝐴) → ¬ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
37 | 34, 35, 36 | 3syl 17 |
. . . . . 6
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → ¬ (¬
𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
38 | 29, 37 | 2falsed 692 |
. . . . 5
⊢ ((𝐵 ∈ ℝ ∧ 𝐴 = -∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
39 | 4, 22, 38 | 3jaodan 1296 |
. . . 4
⊢ ((𝐵 ∈ ℝ ∧ (𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞)) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
40 | 39 | ancoms 266 |
. . 3
⊢ (((𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞) ∧ 𝐵 ∈ ℝ) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
41 | | renepnf 7946 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℝ → 𝐴 ≠ +∞) |
42 | 41 | adantl 275 |
. . . . . . . 8
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → 𝐴 ≠ +∞) |
43 | | neeq2 2350 |
. . . . . . . . 9
⊢ (𝐵 = +∞ → (𝐴 ≠ 𝐵 ↔ 𝐴 ≠ +∞)) |
44 | 43 | adantr 274 |
. . . . . . . 8
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → (𝐴 ≠ 𝐵 ↔ 𝐴 ≠ +∞)) |
45 | 42, 44 | mpbird 166 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → 𝐴 ≠ 𝐵) |
46 | 45 | neneqd 2357 |
. . . . . 6
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → ¬
𝐴 = 𝐵) |
47 | | ltpnf 9716 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℝ → 𝐴 < +∞) |
48 | 47 | adantl 275 |
. . . . . . . 8
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → 𝐴 < +∞) |
49 | | breq2 3986 |
. . . . . . . . 9
⊢ (𝐵 = +∞ → (𝐴 < 𝐵 ↔ 𝐴 < +∞)) |
50 | 49 | adantr 274 |
. . . . . . . 8
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → (𝐴 < 𝐵 ↔ 𝐴 < +∞)) |
51 | 48, 50 | mpbird 166 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → 𝐴 < 𝐵) |
52 | 51, 35, 36 | 3syl 17 |
. . . . . 6
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → ¬
(¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
53 | 46, 52 | 2falsed 692 |
. . . . 5
⊢ ((𝐵 = +∞ ∧ 𝐴 ∈ ℝ) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
54 | | eqtr3 2185 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → 𝐵 = 𝐴) |
55 | 54 | eqcomd 2171 |
. . . . . 6
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → 𝐴 = 𝐵) |
56 | | pnfxr 7951 |
. . . . . . . . 9
⊢ +∞
∈ ℝ* |
57 | | xrltnr 9715 |
. . . . . . . . 9
⊢ (+∞
∈ ℝ* → ¬ +∞ <
+∞) |
58 | 56, 57 | ax-mp 5 |
. . . . . . . 8
⊢ ¬
+∞ < +∞ |
59 | | breq12 3987 |
. . . . . . . . 9
⊢ ((𝐴 = +∞ ∧ 𝐵 = +∞) → (𝐴 < 𝐵 ↔ +∞ <
+∞)) |
60 | 59 | ancoms 266 |
. . . . . . . 8
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → (𝐴 < 𝐵 ↔ +∞ <
+∞)) |
61 | 58, 60 | mtbiri 665 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → ¬ 𝐴 < 𝐵) |
62 | | breq12 3987 |
. . . . . . . 8
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → (𝐵 < 𝐴 ↔ +∞ <
+∞)) |
63 | 58, 62 | mtbiri 665 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → ¬ 𝐵 < 𝐴) |
64 | 61, 63 | jca 304 |
. . . . . 6
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
65 | 55, 64 | 2thd 174 |
. . . . 5
⊢ ((𝐵 = +∞ ∧ 𝐴 = +∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
66 | | mnfnepnf 7954 |
. . . . . . . . 9
⊢ -∞
≠ +∞ |
67 | | eqeq12 2178 |
. . . . . . . . . 10
⊢ ((𝐴 = -∞ ∧ 𝐵 = +∞) → (𝐴 = 𝐵 ↔ -∞ =
+∞)) |
68 | 67 | necon3bid 2377 |
. . . . . . . . 9
⊢ ((𝐴 = -∞ ∧ 𝐵 = +∞) → (𝐴 ≠ 𝐵 ↔ -∞ ≠
+∞)) |
69 | 66, 68 | mpbiri 167 |
. . . . . . . 8
⊢ ((𝐴 = -∞ ∧ 𝐵 = +∞) → 𝐴 ≠ 𝐵) |
70 | 69 | ancoms 266 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 = -∞) → 𝐴 ≠ 𝐵) |
71 | 70 | neneqd 2357 |
. . . . . 6
⊢ ((𝐵 = +∞ ∧ 𝐴 = -∞) → ¬ 𝐴 = 𝐵) |
72 | | mnfltpnf 9721 |
. . . . . . . . 9
⊢ -∞
< +∞ |
73 | | breq12 3987 |
. . . . . . . . 9
⊢ ((𝐴 = -∞ ∧ 𝐵 = +∞) → (𝐴 < 𝐵 ↔ -∞ <
+∞)) |
74 | 72, 73 | mpbiri 167 |
. . . . . . . 8
⊢ ((𝐴 = -∞ ∧ 𝐵 = +∞) → 𝐴 < 𝐵) |
75 | 74 | ancoms 266 |
. . . . . . 7
⊢ ((𝐵 = +∞ ∧ 𝐴 = -∞) → 𝐴 < 𝐵) |
76 | 75, 35, 36 | 3syl 17 |
. . . . . 6
⊢ ((𝐵 = +∞ ∧ 𝐴 = -∞) → ¬ (¬
𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
77 | 71, 76 | 2falsed 692 |
. . . . 5
⊢ ((𝐵 = +∞ ∧ 𝐴 = -∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
78 | 53, 65, 77 | 3jaodan 1296 |
. . . 4
⊢ ((𝐵 = +∞ ∧ (𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞)) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
79 | 78 | ancoms 266 |
. . 3
⊢ (((𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞) ∧ 𝐵 = +∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
80 | | renemnf 7947 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℝ → 𝐴 ≠ -∞) |
81 | 80 | adantl 275 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → 𝐴 ≠ -∞) |
82 | | neeq2 2350 |
. . . . . . . . 9
⊢ (𝐵 = -∞ → (𝐴 ≠ 𝐵 ↔ 𝐴 ≠ -∞)) |
83 | 82 | adantr 274 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → (𝐴 ≠ 𝐵 ↔ 𝐴 ≠ -∞)) |
84 | 81, 83 | mpbird 166 |
. . . . . . 7
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → 𝐴 ≠ 𝐵) |
85 | 84 | neneqd 2357 |
. . . . . 6
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → ¬
𝐴 = 𝐵) |
86 | | mnflt 9719 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℝ → -∞
< 𝐴) |
87 | 86 | adantl 275 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → -∞
< 𝐴) |
88 | | breq1 3985 |
. . . . . . . . 9
⊢ (𝐵 = -∞ → (𝐵 < 𝐴 ↔ -∞ < 𝐴)) |
89 | 88 | adantr 274 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → (𝐵 < 𝐴 ↔ -∞ < 𝐴)) |
90 | 87, 89 | mpbird 166 |
. . . . . . 7
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → 𝐵 < 𝐴) |
91 | 90, 20 | syl 14 |
. . . . . 6
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → ¬
(¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
92 | 85, 91 | 2falsed 692 |
. . . . 5
⊢ ((𝐵 = -∞ ∧ 𝐴 ∈ ℝ) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
93 | 66 | neii 2338 |
. . . . . . . . . 10
⊢ ¬
-∞ = +∞ |
94 | | eqeq12 2178 |
. . . . . . . . . 10
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → (𝐵 = 𝐴 ↔ -∞ =
+∞)) |
95 | 93, 94 | mtbiri 665 |
. . . . . . . . 9
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → ¬ 𝐵 = 𝐴) |
96 | 95 | neneqad 2415 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → 𝐵 ≠ 𝐴) |
97 | 96 | necomd 2422 |
. . . . . . 7
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → 𝐴 ≠ 𝐵) |
98 | 97 | neneqd 2357 |
. . . . . 6
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → ¬ 𝐴 = 𝐵) |
99 | | breq12 3987 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → (𝐵 < 𝐴 ↔ -∞ <
+∞)) |
100 | 72, 99 | mpbiri 167 |
. . . . . . 7
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → 𝐵 < 𝐴) |
101 | 100, 20 | syl 14 |
. . . . . 6
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → ¬ (¬
𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
102 | 98, 101 | 2falsed 692 |
. . . . 5
⊢ ((𝐵 = -∞ ∧ 𝐴 = +∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
103 | | eqtr3 2185 |
. . . . . . 7
⊢ ((𝐴 = -∞ ∧ 𝐵 = -∞) → 𝐴 = 𝐵) |
104 | 103 | ancoms 266 |
. . . . . 6
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → 𝐴 = 𝐵) |
105 | | mnfxr 7955 |
. . . . . . . . 9
⊢ -∞
∈ ℝ* |
106 | | xrltnr 9715 |
. . . . . . . . 9
⊢ (-∞
∈ ℝ* → ¬ -∞ <
-∞) |
107 | 105, 106 | ax-mp 5 |
. . . . . . . 8
⊢ ¬
-∞ < -∞ |
108 | | breq12 3987 |
. . . . . . . . 9
⊢ ((𝐴 = -∞ ∧ 𝐵 = -∞) → (𝐴 < 𝐵 ↔ -∞ <
-∞)) |
109 | 108 | ancoms 266 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → (𝐴 < 𝐵 ↔ -∞ <
-∞)) |
110 | 107, 109 | mtbiri 665 |
. . . . . . 7
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → ¬ 𝐴 < 𝐵) |
111 | | breq12 3987 |
. . . . . . . 8
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → (𝐵 < 𝐴 ↔ -∞ <
-∞)) |
112 | 107, 111 | mtbiri 665 |
. . . . . . 7
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → ¬ 𝐵 < 𝐴) |
113 | 110, 112 | jca 304 |
. . . . . 6
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴)) |
114 | 104, 113 | 2thd 174 |
. . . . 5
⊢ ((𝐵 = -∞ ∧ 𝐴 = -∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
115 | 92, 102, 114 | 3jaodan 1296 |
. . . 4
⊢ ((𝐵 = -∞ ∧ (𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞)) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
116 | 115 | ancoms 266 |
. . 3
⊢ (((𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞) ∧ 𝐵 = -∞) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
117 | 40, 79, 116 | 3jaodan 1296 |
. 2
⊢ (((𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞) ∧ (𝐵 ∈ ℝ ∨ 𝐵 = +∞ ∨ 𝐵 = -∞)) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |
118 | 1, 2, 117 | syl2anb 289 |
1
⊢ ((𝐴 ∈ ℝ*
∧ 𝐵 ∈
ℝ*) → (𝐴 = 𝐵 ↔ (¬ 𝐴 < 𝐵 ∧ ¬ 𝐵 < 𝐴))) |