Step |
Hyp |
Ref |
Expression |
1 |
|
signsw.p |
⊢ ⨣ = ( 𝑎 ∈ { - 1 , 0 , 1 } , 𝑏 ∈ { - 1 , 0 , 1 } ↦ if ( 𝑏 = 0 , 𝑎 , 𝑏 ) ) |
2 |
|
signsw.w |
⊢ 𝑊 = { 〈 ( Base ‘ ndx ) , { - 1 , 0 , 1 } 〉 , 〈 ( +g ‘ ndx ) , ⨣ 〉 } |
3 |
|
df-pr |
⊢ { - 1 , 1 } = ( { - 1 } ∪ { 1 } ) |
4 |
|
snsstp1 |
⊢ { - 1 } ⊆ { - 1 , 0 , 1 } |
5 |
|
snsstp3 |
⊢ { 1 } ⊆ { - 1 , 0 , 1 } |
6 |
4 5
|
unssi |
⊢ ( { - 1 } ∪ { 1 } ) ⊆ { - 1 , 0 , 1 } |
7 |
3 6
|
eqsstri |
⊢ { - 1 , 1 } ⊆ { - 1 , 0 , 1 } |
8 |
7
|
sseli |
⊢ ( 𝑋 ∈ { - 1 , 1 } → 𝑋 ∈ { - 1 , 0 , 1 } ) |
9 |
1
|
signspval |
⊢ ( ( 𝑋 ∈ { - 1 , 0 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) → ( 𝑋 ⨣ 𝑌 ) = if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ) |
10 |
8 9
|
sylan |
⊢ ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) → ( 𝑋 ⨣ 𝑌 ) = if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ) |
11 |
10
|
neeq1d |
⊢ ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) → ( ( 𝑋 ⨣ 𝑌 ) ≠ 𝑋 ↔ if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ≠ 𝑋 ) ) |
12 |
|
neeq1 |
⊢ ( 𝑋 = if ( 𝑌 = 0 , 𝑋 , 𝑌 ) → ( 𝑋 ≠ 𝑋 ↔ if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ≠ 𝑋 ) ) |
13 |
12
|
bibi1d |
⊢ ( 𝑋 = if ( 𝑌 = 0 , 𝑋 , 𝑌 ) → ( ( 𝑋 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ↔ ( if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) ) |
14 |
|
neeq1 |
⊢ ( 𝑌 = if ( 𝑌 = 0 , 𝑋 , 𝑌 ) → ( 𝑌 ≠ 𝑋 ↔ if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ≠ 𝑋 ) ) |
15 |
14
|
bibi1d |
⊢ ( 𝑌 = if ( 𝑌 = 0 , 𝑋 , 𝑌 ) → ( ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ↔ ( if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) ) |
16 |
|
neirr |
⊢ ¬ 𝑋 ≠ 𝑋 |
17 |
16
|
a1i |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ¬ 𝑋 ≠ 𝑋 ) |
18 |
|
0re |
⊢ 0 ∈ ℝ |
19 |
18
|
ltnri |
⊢ ¬ 0 < 0 |
20 |
|
simpr |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → 𝑌 = 0 ) |
21 |
20
|
oveq2d |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ( 𝑋 · 𝑌 ) = ( 𝑋 · 0 ) ) |
22 |
|
neg1cn |
⊢ - 1 ∈ ℂ |
23 |
|
ax-1cn |
⊢ 1 ∈ ℂ |
24 |
|
prssi |
⊢ ( ( - 1 ∈ ℂ ∧ 1 ∈ ℂ ) → { - 1 , 1 } ⊆ ℂ ) |
25 |
22 23 24
|
mp2an |
⊢ { - 1 , 1 } ⊆ ℂ |
26 |
|
simpll |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → 𝑋 ∈ { - 1 , 1 } ) |
27 |
25 26
|
sselid |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → 𝑋 ∈ ℂ ) |
28 |
27
|
mul01d |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ( 𝑋 · 0 ) = 0 ) |
29 |
21 28
|
eqtrd |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ( 𝑋 · 𝑌 ) = 0 ) |
30 |
29
|
breq1d |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ( ( 𝑋 · 𝑌 ) < 0 ↔ 0 < 0 ) ) |
31 |
19 30
|
mtbiri |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ¬ ( 𝑋 · 𝑌 ) < 0 ) |
32 |
17 31
|
2falsed |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ 𝑌 = 0 ) → ( 𝑋 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
33 |
|
simplr |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → 𝑌 ∈ { - 1 , 0 , 1 } ) |
34 |
|
tpcomb |
⊢ { - 1 , 0 , 1 } = { - 1 , 1 , 0 } |
35 |
33 34
|
eleqtrdi |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → 𝑌 ∈ { - 1 , 1 , 0 } ) |
36 |
|
simpr |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → ¬ 𝑌 = 0 ) |
37 |
36
|
neqned |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → 𝑌 ≠ 0 ) |
38 |
35 37
|
jca |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → ( 𝑌 ∈ { - 1 , 1 , 0 } ∧ 𝑌 ≠ 0 ) ) |
39 |
|
eldifsn |
⊢ ( 𝑌 ∈ ( { - 1 , 1 , 0 } ∖ { 0 } ) ↔ ( 𝑌 ∈ { - 1 , 1 , 0 } ∧ 𝑌 ≠ 0 ) ) |
40 |
|
neg1ne0 |
⊢ - 1 ≠ 0 |
41 |
|
ax-1ne0 |
⊢ 1 ≠ 0 |
42 |
|
diftpsn3 |
⊢ ( ( - 1 ≠ 0 ∧ 1 ≠ 0 ) → ( { - 1 , 1 , 0 } ∖ { 0 } ) = { - 1 , 1 } ) |
43 |
40 41 42
|
mp2an |
⊢ ( { - 1 , 1 , 0 } ∖ { 0 } ) = { - 1 , 1 } |
44 |
43
|
eleq2i |
⊢ ( 𝑌 ∈ ( { - 1 , 1 , 0 } ∖ { 0 } ) ↔ 𝑌 ∈ { - 1 , 1 } ) |
45 |
39 44
|
bitr3i |
⊢ ( ( 𝑌 ∈ { - 1 , 1 , 0 } ∧ 𝑌 ≠ 0 ) ↔ 𝑌 ∈ { - 1 , 1 } ) |
46 |
38 45
|
sylib |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → 𝑌 ∈ { - 1 , 1 } ) |
47 |
|
neirr |
⊢ ¬ - 1 ≠ - 1 |
48 |
|
0le1 |
⊢ 0 ≤ 1 |
49 |
|
1re |
⊢ 1 ∈ ℝ |
50 |
18 49
|
lenlti |
⊢ ( 0 ≤ 1 ↔ ¬ 1 < 0 ) |
51 |
48 50
|
mpbi |
⊢ ¬ 1 < 0 |
52 |
|
neg1mulneg1e1 |
⊢ ( - 1 · - 1 ) = 1 |
53 |
52
|
breq1i |
⊢ ( ( - 1 · - 1 ) < 0 ↔ 1 < 0 ) |
54 |
51 53
|
mtbir |
⊢ ¬ ( - 1 · - 1 ) < 0 |
55 |
47 54
|
2false |
⊢ ( - 1 ≠ - 1 ↔ ( - 1 · - 1 ) < 0 ) |
56 |
|
neeq1 |
⊢ ( 𝑌 = - 1 → ( 𝑌 ≠ - 1 ↔ - 1 ≠ - 1 ) ) |
57 |
|
oveq2 |
⊢ ( 𝑌 = - 1 → ( - 1 · 𝑌 ) = ( - 1 · - 1 ) ) |
58 |
57
|
breq1d |
⊢ ( 𝑌 = - 1 → ( ( - 1 · 𝑌 ) < 0 ↔ ( - 1 · - 1 ) < 0 ) ) |
59 |
56 58
|
bibi12d |
⊢ ( 𝑌 = - 1 → ( ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ↔ ( - 1 ≠ - 1 ↔ ( - 1 · - 1 ) < 0 ) ) ) |
60 |
55 59
|
mpbiri |
⊢ ( 𝑌 = - 1 → ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
61 |
60
|
adantl |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑌 = - 1 ) → ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
62 |
|
neg1rr |
⊢ - 1 ∈ ℝ |
63 |
|
neg1lt0 |
⊢ - 1 < 0 |
64 |
|
0lt1 |
⊢ 0 < 1 |
65 |
62 18 49
|
lttri |
⊢ ( ( - 1 < 0 ∧ 0 < 1 ) → - 1 < 1 ) |
66 |
63 64 65
|
mp2an |
⊢ - 1 < 1 |
67 |
62 66
|
gtneii |
⊢ 1 ≠ - 1 |
68 |
22
|
mulid1i |
⊢ ( - 1 · 1 ) = - 1 |
69 |
68 63
|
eqbrtri |
⊢ ( - 1 · 1 ) < 0 |
70 |
67 69
|
2th |
⊢ ( 1 ≠ - 1 ↔ ( - 1 · 1 ) < 0 ) |
71 |
|
neeq1 |
⊢ ( 𝑌 = 1 → ( 𝑌 ≠ - 1 ↔ 1 ≠ - 1 ) ) |
72 |
|
oveq2 |
⊢ ( 𝑌 = 1 → ( - 1 · 𝑌 ) = ( - 1 · 1 ) ) |
73 |
72
|
breq1d |
⊢ ( 𝑌 = 1 → ( ( - 1 · 𝑌 ) < 0 ↔ ( - 1 · 1 ) < 0 ) ) |
74 |
71 73
|
bibi12d |
⊢ ( 𝑌 = 1 → ( ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ↔ ( 1 ≠ - 1 ↔ ( - 1 · 1 ) < 0 ) ) ) |
75 |
70 74
|
mpbiri |
⊢ ( 𝑌 = 1 → ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
76 |
75
|
adantl |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑌 = 1 ) → ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
77 |
|
elpri |
⊢ ( 𝑌 ∈ { - 1 , 1 } → ( 𝑌 = - 1 ∨ 𝑌 = 1 ) ) |
78 |
61 76 77
|
mpjaodan |
⊢ ( 𝑌 ∈ { - 1 , 1 } → ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
79 |
78
|
adantr |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑋 = - 1 ) → ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
80 |
|
neeq2 |
⊢ ( 𝑋 = - 1 → ( 𝑌 ≠ 𝑋 ↔ 𝑌 ≠ - 1 ) ) |
81 |
|
oveq1 |
⊢ ( 𝑋 = - 1 → ( 𝑋 · 𝑌 ) = ( - 1 · 𝑌 ) ) |
82 |
81
|
breq1d |
⊢ ( 𝑋 = - 1 → ( ( 𝑋 · 𝑌 ) < 0 ↔ ( - 1 · 𝑌 ) < 0 ) ) |
83 |
80 82
|
bibi12d |
⊢ ( 𝑋 = - 1 → ( ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ↔ ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) ) |
84 |
83
|
adantl |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑋 = - 1 ) → ( ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ↔ ( 𝑌 ≠ - 1 ↔ ( - 1 · 𝑌 ) < 0 ) ) ) |
85 |
79 84
|
mpbird |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑋 = - 1 ) → ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
86 |
46 85
|
sylan |
⊢ ( ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) ∧ 𝑋 = - 1 ) → ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
87 |
67
|
necomi |
⊢ - 1 ≠ 1 |
88 |
22 23
|
mulcomi |
⊢ ( - 1 · 1 ) = ( 1 · - 1 ) |
89 |
88
|
breq1i |
⊢ ( ( - 1 · 1 ) < 0 ↔ ( 1 · - 1 ) < 0 ) |
90 |
69 89
|
mpbi |
⊢ ( 1 · - 1 ) < 0 |
91 |
87 90
|
2th |
⊢ ( - 1 ≠ 1 ↔ ( 1 · - 1 ) < 0 ) |
92 |
|
neeq1 |
⊢ ( 𝑌 = - 1 → ( 𝑌 ≠ 1 ↔ - 1 ≠ 1 ) ) |
93 |
|
oveq2 |
⊢ ( 𝑌 = - 1 → ( 1 · 𝑌 ) = ( 1 · - 1 ) ) |
94 |
93
|
breq1d |
⊢ ( 𝑌 = - 1 → ( ( 1 · 𝑌 ) < 0 ↔ ( 1 · - 1 ) < 0 ) ) |
95 |
92 94
|
bibi12d |
⊢ ( 𝑌 = - 1 → ( ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ↔ ( - 1 ≠ 1 ↔ ( 1 · - 1 ) < 0 ) ) ) |
96 |
91 95
|
mpbiri |
⊢ ( 𝑌 = - 1 → ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) |
97 |
96
|
adantl |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑌 = - 1 ) → ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) |
98 |
|
neirr |
⊢ ¬ 1 ≠ 1 |
99 |
23
|
mulid1i |
⊢ ( 1 · 1 ) = 1 |
100 |
99
|
breq1i |
⊢ ( ( 1 · 1 ) < 0 ↔ 1 < 0 ) |
101 |
51 100
|
mtbir |
⊢ ¬ ( 1 · 1 ) < 0 |
102 |
98 101
|
2false |
⊢ ( 1 ≠ 1 ↔ ( 1 · 1 ) < 0 ) |
103 |
|
neeq1 |
⊢ ( 𝑌 = 1 → ( 𝑌 ≠ 1 ↔ 1 ≠ 1 ) ) |
104 |
|
oveq2 |
⊢ ( 𝑌 = 1 → ( 1 · 𝑌 ) = ( 1 · 1 ) ) |
105 |
104
|
breq1d |
⊢ ( 𝑌 = 1 → ( ( 1 · 𝑌 ) < 0 ↔ ( 1 · 1 ) < 0 ) ) |
106 |
103 105
|
bibi12d |
⊢ ( 𝑌 = 1 → ( ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ↔ ( 1 ≠ 1 ↔ ( 1 · 1 ) < 0 ) ) ) |
107 |
102 106
|
mpbiri |
⊢ ( 𝑌 = 1 → ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) |
108 |
107
|
adantl |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑌 = 1 ) → ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) |
109 |
97 108 77
|
mpjaodan |
⊢ ( 𝑌 ∈ { - 1 , 1 } → ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) |
110 |
109
|
adantr |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑋 = 1 ) → ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) |
111 |
|
neeq2 |
⊢ ( 𝑋 = 1 → ( 𝑌 ≠ 𝑋 ↔ 𝑌 ≠ 1 ) ) |
112 |
|
oveq1 |
⊢ ( 𝑋 = 1 → ( 𝑋 · 𝑌 ) = ( 1 · 𝑌 ) ) |
113 |
112
|
breq1d |
⊢ ( 𝑋 = 1 → ( ( 𝑋 · 𝑌 ) < 0 ↔ ( 1 · 𝑌 ) < 0 ) ) |
114 |
111 113
|
bibi12d |
⊢ ( 𝑋 = 1 → ( ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ↔ ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) ) |
115 |
114
|
adantl |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑋 = 1 ) → ( ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ↔ ( 𝑌 ≠ 1 ↔ ( 1 · 𝑌 ) < 0 ) ) ) |
116 |
110 115
|
mpbird |
⊢ ( ( 𝑌 ∈ { - 1 , 1 } ∧ 𝑋 = 1 ) → ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
117 |
46 116
|
sylan |
⊢ ( ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) ∧ 𝑋 = 1 ) → ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
118 |
|
elpri |
⊢ ( 𝑋 ∈ { - 1 , 1 } → ( 𝑋 = - 1 ∨ 𝑋 = 1 ) ) |
119 |
118
|
ad2antrr |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → ( 𝑋 = - 1 ∨ 𝑋 = 1 ) ) |
120 |
86 117 119
|
mpjaodan |
⊢ ( ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) ∧ ¬ 𝑌 = 0 ) → ( 𝑌 ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
121 |
13 15 32 120
|
ifbothda |
⊢ ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) → ( if ( 𝑌 = 0 , 𝑋 , 𝑌 ) ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |
122 |
11 121
|
bitrd |
⊢ ( ( 𝑋 ∈ { - 1 , 1 } ∧ 𝑌 ∈ { - 1 , 0 , 1 } ) → ( ( 𝑋 ⨣ 𝑌 ) ≠ 𝑋 ↔ ( 𝑋 · 𝑌 ) < 0 ) ) |