Database
BASIC REAL AND COMPLEX FUNCTIONS
Basic number theory
Quadratic residues and the Legendre symbol
lgsdir2lem5
Next ⟩
lgsdir2
Metamath Proof Explorer
Ascii
Unicode
Theorem
lgsdir2lem5
Description:
Lemma for
lgsdir2
.
(Contributed by
Mario Carneiro
, 4-Feb-2015)
Ref
Expression
Assertion
lgsdir2lem5
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
∈
3
5
∧
B
mod
8
∈
3
5
→
A
B
mod
8
∈
1
7
Proof
Step
Hyp
Ref
Expression
1
ovex
⊢
A
mod
8
∈
V
2
1
elpr
⊢
A
mod
8
∈
3
5
↔
A
mod
8
=
3
∨
A
mod
8
=
5
3
ovex
⊢
B
mod
8
∈
V
4
3
elpr
⊢
B
mod
8
∈
3
5
↔
B
mod
8
=
3
∨
B
mod
8
=
5
5
2
4
anbi12i
⊢
A
mod
8
∈
3
5
∧
B
mod
8
∈
3
5
↔
A
mod
8
=
3
∨
A
mod
8
=
5
∧
B
mod
8
=
3
∨
B
mod
8
=
5
6
simpll
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
A
∈
ℤ
7
3z
⊢
3
∈
ℤ
8
7
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
3
∈
ℤ
9
simplr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
B
∈
ℤ
10
8re
⊢
8
∈
ℝ
11
8pos
⊢
0
<
8
12
10
11
elrpii
⊢
8
∈
ℝ
+
13
12
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
8
∈
ℝ
+
14
simprl
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
A
mod
8
=
3
15
lgsdir2lem1
⊢
1
mod
8
=
1
∧
-1
mod
8
=
7
∧
3
mod
8
=
3
∧
-3
mod
8
=
5
16
15
simpri
⊢
3
mod
8
=
3
∧
-3
mod
8
=
5
17
16
simpli
⊢
3
mod
8
=
3
18
14
17
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
A
mod
8
=
3
mod
8
19
simprr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
B
mod
8
=
3
20
19
17
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
B
mod
8
=
3
mod
8
21
6
8
9
8
13
18
20
modmul12d
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
A
B
mod
8
=
3
⋅
3
mod
8
22
21
orcd
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
3
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
23
22
ex
⊢
A
∈
ℤ
∧
B
∈
ℤ
→
A
mod
8
=
3
∧
B
mod
8
=
3
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
24
simpll
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
∈
ℤ
25
znegcl
⊢
3
∈
ℤ
→
−
3
∈
ℤ
26
7
25
mp1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
−
3
∈
ℤ
27
simplr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
B
∈
ℤ
28
7
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
3
∈
ℤ
29
12
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
8
∈
ℝ
+
30
simprl
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
mod
8
=
5
31
16
simpri
⊢
-3
mod
8
=
5
32
30
31
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
mod
8
=
-3
mod
8
33
simprr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
B
mod
8
=
3
34
33
17
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
B
mod
8
=
3
mod
8
35
24
26
27
28
29
32
34
modmul12d
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
B
mod
8
=
-3
⋅
3
mod
8
36
3cn
⊢
3
∈
ℂ
37
36
36
mulneg1i
⊢
-3
⋅
3
=
−
3
⋅
3
38
37
oveq1i
⊢
-3
⋅
3
mod
8
=
−
3
⋅
3
mod
8
39
35
38
eqtrdi
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
B
mod
8
=
−
3
⋅
3
mod
8
40
39
olcd
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
41
40
ex
⊢
A
∈
ℤ
∧
B
∈
ℤ
→
A
mod
8
=
5
∧
B
mod
8
=
3
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
42
simpll
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
∈
ℤ
43
7
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
3
∈
ℤ
44
simplr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
B
∈
ℤ
45
7
25
mp1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
−
3
∈
ℤ
46
12
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
8
∈
ℝ
+
47
simprl
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
mod
8
=
3
48
47
17
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
mod
8
=
3
mod
8
49
simprr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
B
mod
8
=
5
50
49
31
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
B
mod
8
=
-3
mod
8
51
42
43
44
45
46
48
50
modmul12d
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
B
mod
8
=
3
-3
mod
8
52
36
36
mulneg2i
⊢
3
-3
=
−
3
⋅
3
53
52
oveq1i
⊢
3
-3
mod
8
=
−
3
⋅
3
mod
8
54
51
53
eqtrdi
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
B
mod
8
=
−
3
⋅
3
mod
8
55
54
olcd
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
56
55
ex
⊢
A
∈
ℤ
∧
B
∈
ℤ
→
A
mod
8
=
3
∧
B
mod
8
=
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
57
simpll
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
∈
ℤ
58
7
25
mp1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
−
3
∈
ℤ
59
simplr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
B
∈
ℤ
60
12
a1i
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
8
∈
ℝ
+
61
simprl
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
mod
8
=
5
62
61
31
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
mod
8
=
-3
mod
8
63
simprr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
B
mod
8
=
5
64
63
31
eqtr4di
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
B
mod
8
=
-3
mod
8
65
57
58
59
58
60
62
64
modmul12d
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
B
mod
8
=
-3
-3
mod
8
66
36
36
mul2negi
⊢
-3
-3
=
3
⋅
3
67
66
oveq1i
⊢
-3
-3
mod
8
=
3
⋅
3
mod
8
68
65
67
eqtrdi
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
B
mod
8
=
3
⋅
3
mod
8
69
68
orcd
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
70
69
ex
⊢
A
∈
ℤ
∧
B
∈
ℤ
→
A
mod
8
=
5
∧
B
mod
8
=
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
71
23
41
56
70
ccased
⊢
A
∈
ℤ
∧
B
∈
ℤ
→
A
mod
8
=
3
∨
A
mod
8
=
5
∧
B
mod
8
=
3
∨
B
mod
8
=
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
72
5
71
biimtrid
⊢
A
∈
ℤ
∧
B
∈
ℤ
→
A
mod
8
∈
3
5
∧
B
mod
8
∈
3
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
73
72
imp
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
∈
3
5
∧
B
mod
8
∈
3
5
→
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
74
ovex
⊢
A
B
mod
8
∈
V
75
74
elpr
⊢
A
B
mod
8
∈
3
⋅
3
mod
8
−
3
⋅
3
mod
8
↔
A
B
mod
8
=
3
⋅
3
mod
8
∨
A
B
mod
8
=
−
3
⋅
3
mod
8
76
73
75
sylibr
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
∈
3
5
∧
B
mod
8
∈
3
5
→
A
B
mod
8
∈
3
⋅
3
mod
8
−
3
⋅
3
mod
8
77
df-9
⊢
9
=
8
+
1
78
8cn
⊢
8
∈
ℂ
79
ax-1cn
⊢
1
∈
ℂ
80
78
79
addcomi
⊢
8
+
1
=
1
+
8
81
77
80
eqtri
⊢
9
=
1
+
8
82
3t3e9
⊢
3
⋅
3
=
9
83
78
mullidi
⊢
1
⋅
8
=
8
84
83
oveq2i
⊢
1
+
1
⋅
8
=
1
+
8
85
81
82
84
3eqtr4i
⊢
3
⋅
3
=
1
+
1
⋅
8
86
85
oveq1i
⊢
3
⋅
3
mod
8
=
1
+
1
⋅
8
mod
8
87
1re
⊢
1
∈
ℝ
88
1z
⊢
1
∈
ℤ
89
modcyc
⊢
1
∈
ℝ
∧
8
∈
ℝ
+
∧
1
∈
ℤ
→
1
+
1
⋅
8
mod
8
=
1
mod
8
90
87
12
88
89
mp3an
⊢
1
+
1
⋅
8
mod
8
=
1
mod
8
91
86
90
eqtri
⊢
3
⋅
3
mod
8
=
1
mod
8
92
15
simpli
⊢
1
mod
8
=
1
∧
-1
mod
8
=
7
93
92
simpli
⊢
1
mod
8
=
1
94
91
93
eqtri
⊢
3
⋅
3
mod
8
=
1
95
znegcl
⊢
1
∈
ℤ
→
−
1
∈
ℤ
96
88
95
mp1i
⊢
⊤
→
−
1
∈
ℤ
97
3nn
⊢
3
∈
ℕ
98
97
97
nnmulcli
⊢
3
⋅
3
∈
ℕ
99
98
nnzi
⊢
3
⋅
3
∈
ℤ
100
99
a1i
⊢
⊤
→
3
⋅
3
∈
ℤ
101
88
a1i
⊢
⊤
→
1
∈
ℤ
102
12
a1i
⊢
⊤
→
8
∈
ℝ
+
103
eqidd
⊢
⊤
→
-1
mod
8
=
-1
mod
8
104
91
a1i
⊢
⊤
→
3
⋅
3
mod
8
=
1
mod
8
105
96
96
100
101
102
103
104
modmul12d
⊢
⊤
→
-1
3
⋅
3
mod
8
=
-1
⋅
1
mod
8
106
105
mptru
⊢
-1
3
⋅
3
mod
8
=
-1
⋅
1
mod
8
107
36
36
mulcli
⊢
3
⋅
3
∈
ℂ
108
107
mulm1i
⊢
-1
3
⋅
3
=
−
3
⋅
3
109
108
oveq1i
⊢
-1
3
⋅
3
mod
8
=
−
3
⋅
3
mod
8
110
79
mulm1i
⊢
-1
⋅
1
=
−
1
111
110
oveq1i
⊢
-1
⋅
1
mod
8
=
-1
mod
8
112
106
109
111
3eqtr3i
⊢
−
3
⋅
3
mod
8
=
-1
mod
8
113
92
simpri
⊢
-1
mod
8
=
7
114
112
113
eqtri
⊢
−
3
⋅
3
mod
8
=
7
115
94
114
preq12i
⊢
3
⋅
3
mod
8
−
3
⋅
3
mod
8
=
1
7
116
76
115
eleqtrdi
⊢
A
∈
ℤ
∧
B
∈
ℤ
∧
A
mod
8
∈
3
5
∧
B
mod
8
∈
3
5
→
A
B
mod
8
∈
1
7