Metamath Proof Explorer


Theorem zsoring

Description: The surreal integers form an ordered ring. Note that we have to restrict the operations here since No is a proper class. (Contributed by Scott Fenton, 23-Dec-2025)

Ref Expression
Hypotheses zsoring.1 ⊢ ℤ s = Base K
zsoring.2 ⊢ + s ↾ ℤ s × ℤ s = + K
zsoring.3 ⊢ ⋅ s ↾ ℤ s × ℤ s = ⋅ K
zsoring.4 ⊢ ≤ s ∩ ℤ s × ℤ s = ≤ K
zsoring.5 ⊢ 0 s = 0 K
Assertion zsoring ⊢ K ∈ oRing

Proof

Step Hyp Ref Expression
1 zsoring.1 ⊢ ℤ s = Base K
2 zsoring.2 ⊢ + s ↾ ℤ s × ℤ s = + K
3 zsoring.3 ⊢ ⋅ s ↾ ℤ s × ℤ s = ⋅ K
4 zsoring.4 ⊢ ≤ s ∩ ℤ s × ℤ s = ≤ K
5 zsoring.5 ⊢ 0 s = 0 K
6 ovres ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x + s ↾ ℤ s × ℤ s y = x + s y
7 zaddscl ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x + s y ∈ ℤ s
8 6 7 eqeltrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x + s ↾ ℤ s × ℤ s y ∈ ℤ s
9 zno ⊢ x ∈ ℤ s → x ∈ No
10 zno ⊢ y ∈ ℤ s → y ∈ No
11 zno ⊢ z ∈ ℤ s → z ∈ No
12 addsass ⊢ x ∈ No ∧ y ∈ No ∧ z ∈ No → x + s y + s z = x + s y + s z
13 9 10 11 12 syl3an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s y + s z = x + s y + s z
14 6 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y = x + s y
15 14 oveq1d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s y + s ↾ ℤ s × ℤ s z
16 7 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s y ∈ ℤ s
17 simp3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → z ∈ ℤ s
18 16 17 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s y + s ↾ ℤ s × ℤ s z = x + s y + s z
19 15 18 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s y + s z
20 ovres ⊢ y ∈ ℤ s ∧ z ∈ ℤ s → y + s ↾ ℤ s × ℤ s z = y + s z
21 20 3adant1 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y + s ↾ ℤ s × ℤ s z = y + s z
22 21 oveq2d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s z
23 simp1 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ∈ ℤ s
24 zaddscl ⊢ y ∈ ℤ s ∧ z ∈ ℤ s → y + s z ∈ ℤ s
25 24 3adant1 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y + s z ∈ ℤ s
26 23 25 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s z = x + s y + s z
27 22 26 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s y + s z
28 13 19 27 3eqtr4d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
29 0zs ⊢ 0 s ∈ ℤ s
30 ovres ⊢ 0 s ∈ ℤ s ∧ x ∈ ℤ s → 0 s + s ↾ ℤ s × ℤ s x = 0 s + s x
31 29 30 mpan ⊢ x ∈ ℤ s → 0 s + s ↾ ℤ s × ℤ s x = 0 s + s x
32 addslid ⊢ x ∈ No → 0 s + s x = x
33 9 32 syl ⊢ x ∈ ℤ s → 0 s + s x = x
34 31 33 eqtrd ⊢ x ∈ ℤ s → 0 s + s ↾ ℤ s × ℤ s x = x
35 znegscl ⊢ x ∈ ℤ s → + s ⁡ x ∈ ℤ s
36 id ⊢ x ∈ ℤ s → x ∈ ℤ s
37 35 36 ovresd ⊢ x ∈ ℤ s → + s ⁡ x + s ↾ ℤ s × ℤ s x = + s ⁡ x + s x
38 35 znod ⊢ x ∈ ℤ s → + s ⁡ x ∈ No
39 38 9 addscomd ⊢ x ∈ ℤ s → + s ⁡ x + s x = x + s + s ⁡ x
40 9 negsidd ⊢ x ∈ ℤ s → x + s + s ⁡ x = 0 s
41 37 39 40 3eqtrd ⊢ x ∈ ℤ s → + s ⁡ x + s ↾ ℤ s × ℤ s x = 0 s
42 1 2 8 28 29 34 35 41 isgrpi ⊢ K ∈ Grp
43 ovres ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y = x ⋅ s y
44 simpl ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ∈ ℤ s
45 simpr ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → y ∈ ℤ s
46 44 45 zmulscld ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ⋅ s y ∈ ℤ s
47 43 46 eqeltrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
48 mulsass ⊢ x ∈ No ∧ y ∈ No ∧ z ∈ No → x ⋅ s y ⋅ s z = x ⋅ s y ⋅ s z
49 9 10 11 48 syl3an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s y ⋅ s z = x ⋅ s y ⋅ s z
50 43 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y = x ⋅ s y
51 50 oveq1d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s y ⋅ s ↾ ℤ s × ℤ s z
52 simp2 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ∈ ℤ s
53 23 52 zmulscld ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s y ∈ ℤ s
54 53 17 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s y ⋅ s z
55 51 54 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s y ⋅ s z
56 ovres ⊢ y ∈ ℤ s ∧ z ∈ ℤ s → y ⋅ s ↾ ℤ s × ℤ s z = y ⋅ s z
57 56 3adant1 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ⋅ s ↾ ℤ s × ℤ s z = y ⋅ s z
58 57 oveq2d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s z
59 52 17 zmulscld ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ⋅ s z ∈ ℤ s
60 23 59 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s z = x ⋅ s y ⋅ s z
61 58 60 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s y ⋅ s z
62 49 55 61 3eqtr4d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
63 62 3expa ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
64 63 ralrimiva ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → ∀ z ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
65 47 64 jca ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s ∧ ∀ z ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
66 65 rgen2 ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s ∧ ∀ z ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
67 1zs ⊢ 1 s ∈ ℤ s
68 ovres ⊢ 1 s ∈ ℤ s ∧ x ∈ ℤ s → 1 s ⋅ s ↾ ℤ s × ℤ s x = 1 s ⋅ s x
69 67 68 mpan ⊢ x ∈ ℤ s → 1 s ⋅ s ↾ ℤ s × ℤ s x = 1 s ⋅ s x
70 9 mulslidd ⊢ x ∈ ℤ s → 1 s ⋅ s x = x
71 69 70 eqtrd ⊢ x ∈ ℤ s → 1 s ⋅ s ↾ ℤ s × ℤ s x = x
72 ovres ⊢ x ∈ ℤ s ∧ 1 s ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s 1 s = x ⋅ s 1 s
73 67 72 mpan2 ⊢ x ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s 1 s = x ⋅ s 1 s
74 9 mulsridd ⊢ x ∈ ℤ s → x ⋅ s 1 s = x
75 73 74 eqtrd ⊢ x ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s 1 s = x
76 71 75 jca ⊢ x ∈ ℤ s → 1 s ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s 1 s = x
77 76 rgen ⊢ ∀ x ∈ ℤ s 1 s ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s 1 s = x
78 oveq1 ⊢ y = 1 s → y ⋅ s ↾ ℤ s × ℤ s x = 1 s ⋅ s ↾ ℤ s × ℤ s x
79 78 eqeq1d ⊢ y = 1 s → y ⋅ s ↾ ℤ s × ℤ s x = x ↔ 1 s ⋅ s ↾ ℤ s × ℤ s x = x
80 79 ovanraleqv ⊢ y = 1 s → ∀ x ∈ ℤ s y ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s y = x ↔ ∀ x ∈ ℤ s 1 s ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s 1 s = x
81 80 rspcev ⊢ 1 s ∈ ℤ s ∧ ∀ x ∈ ℤ s 1 s ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s 1 s = x → ∃ y ∈ ℤ s ∀ x ∈ ℤ s y ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s y = x
82 67 77 81 mp2an ⊢ ∃ y ∈ ℤ s ∀ x ∈ ℤ s y ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s y = x
83 eqid ⊢ mulGrp K = mulGrp K
84 83 1 mgpbas ⊢ ℤ s = Base mulGrp K
85 83 3 mgpplusg ⊢ ⋅ s ↾ ℤ s × ℤ s = + mulGrp K
86 84 85 ismnd ⊢ mulGrp K ∈ Mnd ↔ ∀ x ∈ ℤ s ∀ y ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s ∧ ∀ z ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z ∧ ∃ y ∈ ℤ s ∀ x ∈ ℤ s y ⋅ s ↾ ℤ s × ℤ s x = x ∧ x ⋅ s ↾ ℤ s × ℤ s y = x
87 66 82 86 mpbir2an ⊢ mulGrp K ∈ Mnd
88 addsdi ⊢ x ∈ No ∧ y ∈ No ∧ z ∈ No → x ⋅ s y + s z = x ⋅ s y + s x ⋅ s z
89 9 10 11 88 syl3an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s y + s z = x ⋅ s y + s x ⋅ s z
90 21 oveq2d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y + s z
91 23 25 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s z = x ⋅ s y + s z
92 90 91 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x ⋅ s y + s z
93 ovres ⊢ x ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s z
94 93 3adant2 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s z
95 50 94 oveq12d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s y + s ↾ ℤ s × ℤ s x ⋅ s z
96 23 17 zmulscld ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s z ∈ ℤ s
97 53 96 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s y + s ↾ ℤ s × ℤ s x ⋅ s z = x ⋅ s y + s x ⋅ s z
98 95 97 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s y + s x ⋅ s z
99 89 92 98 3eqtr4d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s z
100 23 znod ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ∈ No
101 52 znod ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ∈ No
102 17 znod ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → z ∈ No
103 100 101 102 addsdird ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s y ⋅ s z = x ⋅ s z + s y ⋅ s z
104 14 oveq1d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x + s y ⋅ s ↾ ℤ s × ℤ s z
105 16 17 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s y ⋅ s ↾ ℤ s × ℤ s z = x + s y ⋅ s z
106 104 105 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x + s y ⋅ s z
107 94 57 oveq12d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s z + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s z + s ↾ ℤ s × ℤ s y ⋅ s z
108 96 59 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s z + s ↾ ℤ s × ℤ s y ⋅ s z = x ⋅ s z + s y ⋅ s z
109 107 108 eqtrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s z + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s z + s y ⋅ s z
110 103 106 109 3eqtr4d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s z + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
111 99 110 jca ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s z ∧ x + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s z + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
112 111 rgen3 ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s ∀ z ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s z ∧ x + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s z + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
113 1 83 2 3 isring ⊢ K ∈ Ring ↔ K ∈ Grp ∧ mulGrp K ∈ Mnd ∧ ∀ x ∈ ℤ s ∀ y ∈ ℤ s ∀ z ∈ ℤ s x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s z ∧ x + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z = x ⋅ s ↾ ℤ s × ℤ s z + s ↾ ℤ s × ℤ s y ⋅ s ↾ ℤ s × ℤ s z
114 42 87 112 113 mpbir3an ⊢ K ∈ Ring
115 28 3expa ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
116 115 ralrimiva ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → ∀ z ∈ ℤ s x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
117 8 116 jca ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x + s ↾ ℤ s × ℤ s y ∈ ℤ s ∧ ∀ z ∈ ℤ s x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
118 117 rgen2 ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s x + s ↾ ℤ s × ℤ s y ∈ ℤ s ∧ ∀ z ∈ ℤ s x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
119 ovres ⊢ x ∈ ℤ s ∧ 0 s ∈ ℤ s → x + s ↾ ℤ s × ℤ s 0 s = x + s 0 s
120 29 119 mpan2 ⊢ x ∈ ℤ s → x + s ↾ ℤ s × ℤ s 0 s = x + s 0 s
121 9 addsridd ⊢ x ∈ ℤ s → x + s 0 s = x
122 120 121 eqtrd ⊢ x ∈ ℤ s → x + s ↾ ℤ s × ℤ s 0 s = x
123 34 122 jca ⊢ x ∈ ℤ s → 0 s + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s 0 s = x
124 123 rgen ⊢ ∀ x ∈ ℤ s 0 s + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s 0 s = x
125 oveq1 ⊢ y = 0 s → y + s ↾ ℤ s × ℤ s x = 0 s + s ↾ ℤ s × ℤ s x
126 125 eqeq1d ⊢ y = 0 s → y + s ↾ ℤ s × ℤ s x = x ↔ 0 s + s ↾ ℤ s × ℤ s x = x
127 126 ovanraleqv ⊢ y = 0 s → ∀ x ∈ ℤ s y + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s y = x ↔ ∀ x ∈ ℤ s 0 s + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s 0 s = x
128 127 rspcev ⊢ 0 s ∈ ℤ s ∧ ∀ x ∈ ℤ s 0 s + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s 0 s = x → ∃ y ∈ ℤ s ∀ x ∈ ℤ s y + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s y = x
129 29 124 128 mp2an ⊢ ∃ y ∈ ℤ s ∀ x ∈ ℤ s y + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s y = x
130 1 2 ismnd ⊢ K ∈ Mnd ↔ ∀ x ∈ ℤ s ∀ y ∈ ℤ s x + s ↾ ℤ s × ℤ s y ∈ ℤ s ∧ ∀ z ∈ ℤ s x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z = x + s ↾ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z ∧ ∃ y ∈ ℤ s ∀ x ∈ ℤ s y + s ↾ ℤ s × ℤ s x = x ∧ x + s ↾ ℤ s × ℤ s y = x
131 118 129 130 mpbir2an ⊢ K ∈ Mnd
132 42 elexi ⊢ K ∈ V
133 lesid ⊢ x ∈ No → x ≤ s x
134 9 133 syl ⊢ x ∈ ℤ s → x ≤ s x
135 brxp ⊢ x ℤ s × ℤ s x ↔ x ∈ ℤ s ∧ x ∈ ℤ s
136 135 biimpri ⊢ x ∈ ℤ s ∧ x ∈ ℤ s → x ℤ s × ℤ s x
137 136 anidms ⊢ x ∈ ℤ s → x ℤ s × ℤ s x
138 brin ⊢ x ≤ s ∩ ℤ s × ℤ s x ↔ x ≤ s x ∧ x ℤ s × ℤ s x
139 134 137 138 sylanbrc ⊢ x ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s x
140 139 3ad2ant1 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s x
141 brin ⊢ x ≤ s ∩ ℤ s × ℤ s y ↔ x ≤ s y ∧ x ℤ s × ℤ s y
142 brxp ⊢ x ℤ s × ℤ s y ↔ x ∈ ℤ s ∧ y ∈ ℤ s
143 142 biimpri ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ℤ s × ℤ s y
144 143 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ℤ s × ℤ s y
145 144 biantrud ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s y ↔ x ≤ s y ∧ x ℤ s × ℤ s y
146 141 145 bitr4id ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ↔ x ≤ s y
147 brin ⊢ y ≤ s ∩ ℤ s × ℤ s x ↔ y ≤ s x ∧ y ℤ s × ℤ s x
148 brxp ⊢ y ℤ s × ℤ s x ↔ y ∈ ℤ s ∧ x ∈ ℤ s
149 148 biimpri ⊢ y ∈ ℤ s ∧ x ∈ ℤ s → y ℤ s × ℤ s x
150 149 ancoms ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → y ℤ s × ℤ s x
151 150 biantrud ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → y ≤ s x ↔ y ≤ s x ∧ y ℤ s × ℤ s x
152 147 151 bitr4id ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → y ≤ s ∩ ℤ s × ℤ s x ↔ y ≤ s x
153 152 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ≤ s ∩ ℤ s × ℤ s x ↔ y ≤ s x
154 146 153 anbi12d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s x ↔ x ≤ s y ∧ y ≤ s x
155 lestri3 ⊢ x ∈ No ∧ y ∈ No → x = y ↔ x ≤ s y ∧ y ≤ s x
156 9 10 155 syl2an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x = y ↔ x ≤ s y ∧ y ≤ s x
157 156 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x = y ↔ x ≤ s y ∧ y ≤ s x
158 157 biimprd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s y ∧ y ≤ s x → x = y
159 154 158 sylbid ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s x → x = y
160 lestr ⊢ x ∈ No ∧ y ∈ No ∧ z ∈ No → x ≤ s y ∧ y ≤ s z → x ≤ s z
161 9 10 11 160 syl3an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s y ∧ y ≤ s z → x ≤ s z
162 143 biantrud ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ≤ s y ↔ x ≤ s y ∧ x ℤ s × ℤ s y
163 141 162 bitr4id ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ↔ x ≤ s y
164 163 3adant3 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ↔ x ≤ s y
165 brin ⊢ y ≤ s ∩ ℤ s × ℤ s z ↔ y ≤ s z ∧ y ℤ s × ℤ s z
166 brxp ⊢ y ℤ s × ℤ s z ↔ y ∈ ℤ s ∧ z ∈ ℤ s
167 166 biimpri ⊢ y ∈ ℤ s ∧ z ∈ ℤ s → y ℤ s × ℤ s z
168 167 3adant1 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ℤ s × ℤ s z
169 168 biantrud ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ≤ s z ↔ y ≤ s z ∧ y ℤ s × ℤ s z
170 165 169 bitr4id ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y ≤ s ∩ ℤ s × ℤ s z ↔ y ≤ s z
171 164 170 anbi12d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s z ↔ x ≤ s y ∧ y ≤ s z
172 brin ⊢ x ≤ s ∩ ℤ s × ℤ s z ↔ x ≤ s z ∧ x ℤ s × ℤ s z
173 brxp ⊢ x ℤ s × ℤ s z ↔ x ∈ ℤ s ∧ z ∈ ℤ s
174 173 biimpri ⊢ x ∈ ℤ s ∧ z ∈ ℤ s → x ℤ s × ℤ s z
175 174 3adant2 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ℤ s × ℤ s z
176 175 biantrud ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s z ↔ x ≤ s z ∧ x ℤ s × ℤ s z
177 172 176 bitr4id ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s z ↔ x ≤ s z
178 161 171 177 3imtr4d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s z → x ≤ s ∩ ℤ s × ℤ s z
179 140 159 178 3jca ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s x ∧ x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s x → x = y ∧ x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s z → x ≤ s ∩ ℤ s × ℤ s z
180 179 rgen3 ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s ∀ z ∈ ℤ s x ≤ s ∩ ℤ s × ℤ s x ∧ x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s x → x = y ∧ x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s z → x ≤ s ∩ ℤ s × ℤ s z
181 1 4 ispos ⊢ K ∈ Poset ↔ K ∈ V ∧ ∀ x ∈ ℤ s ∀ y ∈ ℤ s ∀ z ∈ ℤ s x ≤ s ∩ ℤ s × ℤ s x ∧ x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s x → x = y ∧ x ≤ s ∩ ℤ s × ℤ s y ∧ y ≤ s ∩ ℤ s × ℤ s z → x ≤ s ∩ ℤ s × ℤ s z
182 132 180 181 mpbir2an ⊢ K ∈ Poset
183 lestric ⊢ x ∈ No ∧ y ∈ No → x ≤ s y ∨ y ≤ s x
184 9 10 183 syl2an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ≤ s y ∨ y ≤ s x
185 163 152 orbi12d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ∨ y ≤ s ∩ ℤ s × ℤ s x ↔ x ≤ s y ∨ y ≤ s x
186 184 185 mpbird ⊢ x ∈ ℤ s ∧ y ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y ∨ y ≤ s ∩ ℤ s × ℤ s x
187 186 rgen2 ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s x ≤ s ∩ ℤ s × ℤ s y ∨ y ≤ s ∩ ℤ s × ℤ s x
188 1 4 istos ⊢ K ∈ Toset ↔ K ∈ Poset ∧ ∀ x ∈ ℤ s ∀ y ∈ ℤ s x ≤ s ∩ ℤ s × ℤ s y ∨ y ≤ s ∩ ℤ s × ℤ s x
189 182 187 188 mpbir2an ⊢ K ∈ Toset
190 leadds1 ⊢ x ∈ No ∧ y ∈ No ∧ z ∈ No → x ≤ s y ↔ x + s z ≤ s y + s z
191 9 10 11 190 syl3an ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s y ↔ x + s z ≤ s y + s z
192 191 biimpd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s y → x + s z ≤ s y + s z
193 23 17 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s z = x + s z
194 52 17 ovresd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → y + s ↾ ℤ s × ℤ s z = y + s z
195 193 194 breq12d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s z ≤ s ∩ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z ↔ x + s z ≤ s ∩ ℤ s × ℤ s y + s z
196 brin ⊢ x + s z ≤ s ∩ ℤ s × ℤ s y + s z ↔ x + s z ≤ s y + s z ∧ x + s z ℤ s × ℤ s y + s z
197 zaddscl ⊢ x ∈ ℤ s ∧ z ∈ ℤ s → x + s z ∈ ℤ s
198 197 3adant2 ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s z ∈ ℤ s
199 brxp ⊢ x + s z ℤ s × ℤ s y + s z ↔ x + s z ∈ ℤ s ∧ y + s z ∈ ℤ s
200 198 25 199 sylanbrc ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s z ℤ s × ℤ s y + s z
201 200 biantrud ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s z ≤ s y + s z ↔ x + s z ≤ s y + s z ∧ x + s z ℤ s × ℤ s y + s z
202 196 201 bitr4id ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s z ≤ s ∩ ℤ s × ℤ s y + s z ↔ x + s z ≤ s y + s z
203 195 202 bitrd ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x + s ↾ ℤ s × ℤ s z ≤ s ∩ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z ↔ x + s z ≤ s y + s z
204 192 146 203 3imtr4d ⊢ x ∈ ℤ s ∧ y ∈ ℤ s ∧ z ∈ ℤ s → x ≤ s ∩ ℤ s × ℤ s y → x + s ↾ ℤ s × ℤ s z ≤ s ∩ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
205 204 rgen3 ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s ∀ z ∈ ℤ s x ≤ s ∩ ℤ s × ℤ s y → x + s ↾ ℤ s × ℤ s z ≤ s ∩ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
206 1 2 4 isomnd ⊢ K ∈ oMnd ↔ K ∈ Mnd ∧ K ∈ Toset ∧ ∀ x ∈ ℤ s ∀ y ∈ ℤ s ∀ z ∈ ℤ s x ≤ s ∩ ℤ s × ℤ s y → x + s ↾ ℤ s × ℤ s z ≤ s ∩ ℤ s × ℤ s y + s ↾ ℤ s × ℤ s z
207 131 189 205 206 mpbir3an ⊢ K ∈ oMnd
208 isogrp ⊢ K ∈ oGrp ↔ K ∈ Grp ∧ K ∈ oMnd
209 42 207 208 mpbir2an ⊢ K ∈ oGrp
210 simplr ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → x ∈ ℤ s
211 210 znod ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → x ∈ No
212 simprr ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → y ∈ ℤ s
213 212 znod ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → y ∈ No
214 simpll ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → 0 s ≤ s x
215 simprl ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → 0 s ≤ s y
216 211 213 214 215 mulsge0d ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → 0 s ≤ s x ⋅ s y
217 210 212 ovresd ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y = x ⋅ s y
218 216 217 breqtrrd ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → 0 s ≤ s x ⋅ s ↾ ℤ s × ℤ s y
219 210 212 zmulscld ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → x ⋅ s y ∈ ℤ s
220 217 219 eqeltrd ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
221 218 220 jca ⊢ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s → 0 s ≤ s x ⋅ s ↾ ℤ s × ℤ s y ∧ x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
222 brin ⊢ 0 s ≤ s ∩ ℤ s × ℤ s x ↔ 0 s ≤ s x ∧ 0 s ℤ s × ℤ s x
223 brxp ⊢ 0 s ℤ s × ℤ s x ↔ 0 s ∈ ℤ s ∧ x ∈ ℤ s
224 29 223 mpbiran ⊢ 0 s ℤ s × ℤ s x ↔ x ∈ ℤ s
225 224 anbi2i ⊢ 0 s ≤ s x ∧ 0 s ℤ s × ℤ s x ↔ 0 s ≤ s x ∧ x ∈ ℤ s
226 222 225 bitri ⊢ 0 s ≤ s ∩ ℤ s × ℤ s x ↔ 0 s ≤ s x ∧ x ∈ ℤ s
227 brin ⊢ 0 s ≤ s ∩ ℤ s × ℤ s y ↔ 0 s ≤ s y ∧ 0 s ℤ s × ℤ s y
228 brxp ⊢ 0 s ℤ s × ℤ s y ↔ 0 s ∈ ℤ s ∧ y ∈ ℤ s
229 29 228 mpbiran ⊢ 0 s ℤ s × ℤ s y ↔ y ∈ ℤ s
230 229 anbi2i ⊢ 0 s ≤ s y ∧ 0 s ℤ s × ℤ s y ↔ 0 s ≤ s y ∧ y ∈ ℤ s
231 227 230 bitri ⊢ 0 s ≤ s ∩ ℤ s × ℤ s y ↔ 0 s ≤ s y ∧ y ∈ ℤ s
232 226 231 anbi12i ⊢ 0 s ≤ s ∩ ℤ s × ℤ s x ∧ 0 s ≤ s ∩ ℤ s × ℤ s y ↔ 0 s ≤ s x ∧ x ∈ ℤ s ∧ 0 s ≤ s y ∧ y ∈ ℤ s
233 brin ⊢ 0 s ≤ s ∩ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y ↔ 0 s ≤ s x ⋅ s ↾ ℤ s × ℤ s y ∧ 0 s ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y
234 brxp ⊢ 0 s ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y ↔ 0 s ∈ ℤ s ∧ x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
235 29 234 mpbiran ⊢ 0 s ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y ↔ x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
236 235 anbi2i ⊢ 0 s ≤ s x ⋅ s ↾ ℤ s × ℤ s y ∧ 0 s ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y ↔ 0 s ≤ s x ⋅ s ↾ ℤ s × ℤ s y ∧ x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
237 233 236 bitri ⊢ 0 s ≤ s ∩ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y ↔ 0 s ≤ s x ⋅ s ↾ ℤ s × ℤ s y ∧ x ⋅ s ↾ ℤ s × ℤ s y ∈ ℤ s
238 221 232 237 3imtr4i ⊢ 0 s ≤ s ∩ ℤ s × ℤ s x ∧ 0 s ≤ s ∩ ℤ s × ℤ s y → 0 s ≤ s ∩ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y
239 238 rgen2w ⊢ ∀ x ∈ ℤ s ∀ y ∈ ℤ s 0 s ≤ s ∩ ℤ s × ℤ s x ∧ 0 s ≤ s ∩ ℤ s × ℤ s y → 0 s ≤ s ∩ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y
240 1 5 3 4 isorng ⊢ K ∈ oRing ↔ K ∈ Ring ∧ K ∈ oGrp ∧ ∀ x ∈ ℤ s ∀ y ∈ ℤ s 0 s ≤ s ∩ ℤ s × ℤ s x ∧ 0 s ≤ s ∩ ℤ s × ℤ s y → 0 s ≤ s ∩ ℤ s × ℤ s x ⋅ s ↾ ℤ s × ℤ s y
241 114 209 239 240 mpbir3an ⊢ K ∈ oRing