Metamath Proof Explorer


Theorem nprmdvdsfacm1lem4

Description: Lemma 4 for nprmdvdsfacm1 . (Contributed by AV, 7-Apr-2026)

Ref Expression
Assertion nprmdvdsfacm1lem4 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N ∥ N − 1 !

Proof

Step Hyp Ref Expression
1 eluzelz ⊢ N ∈ ℤ ≥ 6 → N ∈ ℤ
2 1 3ad2ant1 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N ∈ ℤ
3 elfzoelz ⊢ A ∈ 2 ..^ N → A ∈ ℤ
4 id ⊢ A ∈ ℤ → A ∈ ℤ
5 2z ⊢ 2 ∈ ℤ
6 5 a1i ⊢ A ∈ ℤ → 2 ∈ ℤ
7 6 4 zmulcld ⊢ A ∈ ℤ → 2 ⁢ A ∈ ℤ
8 4 7 zmulcld ⊢ A ∈ ℤ → A ⁢ 2 ⁢ A ∈ ℤ
9 3 8 syl ⊢ A ∈ 2 ..^ N → A ⁢ 2 ⁢ A ∈ ℤ
10 9 3ad2ant2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → A ⁢ 2 ⁢ A ∈ ℤ
11 1z ⊢ 1 ∈ ℤ
12 6nn ⊢ 6 ∈ ℕ
13 12 nnzi ⊢ 6 ∈ ℤ
14 1re ⊢ 1 ∈ ℝ
15 6re ⊢ 6 ∈ ℝ
16 1lt6 ⊢ 1 < 6
17 14 15 16 ltleii ⊢ 1 ≤ 6
18 eluz2 ⊢ 6 ∈ ℤ ≥ 1 ↔ 1 ∈ ℤ ∧ 6 ∈ ℤ ∧ 1 ≤ 6
19 11 13 17 18 mpbir3an ⊢ 6 ∈ ℤ ≥ 1
20 uzss ⊢ 6 ∈ ℤ ≥ 1 → ℤ ≥ 6 ⊆ ℤ ≥ 1
21 19 20 ax-mp ⊢ ℤ ≥ 6 ⊆ ℤ ≥ 1
22 21 sseli ⊢ N ∈ ℤ ≥ 6 → N ∈ ℤ ≥ 1
23 elnnuz ⊢ N ∈ ℕ ↔ N ∈ ℤ ≥ 1
24 22 23 sylibr ⊢ N ∈ ℤ ≥ 6 → N ∈ ℕ
25 24 3ad2ant1 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N ∈ ℕ
26 nnm1nn0 ⊢ N ∈ ℕ → N − 1 ∈ ℕ 0
27 25 26 syl ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N − 1 ∈ ℕ 0
28 27 faccld ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N − 1 ! ∈ ℕ
29 28 nnzd ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N − 1 ! ∈ ℤ
30 nprmdvdsfacm1lem1 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N ∥ A ⁢ 2 ⁢ A
31 elfzo2 ⊢ A ∈ 2 ..^ N ↔ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N
32 2eluzge1 ⊢ 2 ∈ ℤ ≥ 1
33 uzss ⊢ 2 ∈ ℤ ≥ 1 → ℤ ≥ 2 ⊆ ℤ ≥ 1
34 32 33 ax-mp ⊢ ℤ ≥ 2 ⊆ ℤ ≥ 1
35 34 sseli ⊢ A ∈ ℤ ≥ 2 → A ∈ ℤ ≥ 1
36 35 3ad2ant1 ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → A ∈ ℤ ≥ 1
37 5 a1i ⊢ A ∈ ℤ ≥ 2 → 2 ∈ ℤ
38 eluzelz ⊢ A ∈ ℤ ≥ 2 → A ∈ ℤ
39 37 38 zmulcld ⊢ A ∈ ℤ ≥ 2 → 2 ⁢ A ∈ ℤ
40 39 3ad2ant1 ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → 2 ⁢ A ∈ ℤ
41 1lt2 ⊢ 1 < 2
42 eluz2 ⊢ A ∈ ℤ ≥ 2 ↔ 2 ∈ ℤ ∧ A ∈ ℤ ∧ 2 ≤ A
43 zre ⊢ A ∈ ℤ → A ∈ ℝ
44 43 3ad2ant2 ⊢ 2 ∈ ℤ ∧ A ∈ ℤ ∧ 2 ≤ A → A ∈ ℝ
45 2re ⊢ 2 ∈ ℝ
46 45 a1i ⊢ 2 ∈ ℤ ∧ A ∈ ℤ ∧ 2 ≤ A → 2 ∈ ℝ
47 2pos ⊢ 0 < 2
48 0red ⊢ A ∈ ℤ → 0 ∈ ℝ
49 45 a1i ⊢ A ∈ ℤ → 2 ∈ ℝ
50 48 49 43 3jca ⊢ A ∈ ℤ → 0 ∈ ℝ ∧ 2 ∈ ℝ ∧ A ∈ ℝ
51 ltletr ⊢ 0 ∈ ℝ ∧ 2 ∈ ℝ ∧ A ∈ ℝ → 0 < 2 ∧ 2 ≤ A → 0 < A
52 50 51 syl ⊢ A ∈ ℤ → 0 < 2 ∧ 2 ≤ A → 0 < A
53 47 52 mpani ⊢ A ∈ ℤ → 2 ≤ A → 0 < A
54 53 imp ⊢ A ∈ ℤ ∧ 2 ≤ A → 0 < A
55 54 3adant1 ⊢ 2 ∈ ℤ ∧ A ∈ ℤ ∧ 2 ≤ A → 0 < A
56 44 46 55 3jca ⊢ 2 ∈ ℤ ∧ A ∈ ℤ ∧ 2 ≤ A → A ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < A
57 42 56 sylbi ⊢ A ∈ ℤ ≥ 2 → A ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < A
58 57 3ad2ant1 ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → A ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < A
59 ltmulgt12 ⊢ A ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < A → 1 < 2 ↔ A < 2 ⁢ A
60 58 59 syl ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → 1 < 2 ↔ A < 2 ⁢ A
61 41 60 mpbii ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → A < 2 ⁢ A
62 36 40 61 3jca ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → A ∈ ℤ ≥ 1 ∧ 2 ⁢ A ∈ ℤ ∧ A < 2 ⁢ A
63 31 62 sylbi ⊢ A ∈ 2 ..^ N → A ∈ ℤ ≥ 1 ∧ 2 ⁢ A ∈ ℤ ∧ A < 2 ⁢ A
64 elfzo2 ⊢ A ∈ 1 ..^ 2 ⁢ A ↔ A ∈ ℤ ≥ 1 ∧ 2 ⁢ A ∈ ℤ ∧ A < 2 ⁢ A
65 63 64 sylibr ⊢ A ∈ 2 ..^ N → A ∈ 1 ..^ 2 ⁢ A
66 65 3ad2ant2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → A ∈ 1 ..^ 2 ⁢ A
67 11 a1i ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 1 ∈ ℤ
68 5 a1i ⊢ A ∈ 2 ..^ N → 2 ∈ ℤ
69 68 3 zmulcld ⊢ A ∈ 2 ..^ N → 2 ⁢ A ∈ ℤ
70 69 3ad2ant2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 2 ⁢ A ∈ ℤ
71 47 a1i ⊢ A ∈ ℤ → 0 < 2
72 lemul2 ⊢ 2 ∈ ℝ ∧ A ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < 2 → 2 ≤ A ↔ 2 ⋅ 2 ≤ 2 ⁢ A
73 49 43 49 71 72 syl112anc ⊢ A ∈ ℤ → 2 ≤ A ↔ 2 ⋅ 2 ≤ 2 ⁢ A
74 1red ⊢ A ∈ ℤ ∧ 2 ⋅ 2 ≤ 2 ⁢ A → 1 ∈ ℝ
75 2t2e4 ⊢ 2 ⋅ 2 = 4
76 4re ⊢ 4 ∈ ℝ
77 75 76 eqeltri ⊢ 2 ⋅ 2 ∈ ℝ
78 77 a1i ⊢ A ∈ ℤ ∧ 2 ⋅ 2 ≤ 2 ⁢ A → 2 ⋅ 2 ∈ ℝ
79 7 zred ⊢ A ∈ ℤ → 2 ⁢ A ∈ ℝ
80 79 adantr ⊢ A ∈ ℤ ∧ 2 ⋅ 2 ≤ 2 ⁢ A → 2 ⁢ A ∈ ℝ
81 1lt4 ⊢ 1 < 4
82 14 76 81 ltleii ⊢ 1 ≤ 4
83 82 75 breqtrri ⊢ 1 ≤ 2 ⋅ 2
84 83 a1i ⊢ A ∈ ℤ ∧ 2 ⋅ 2 ≤ 2 ⁢ A → 1 ≤ 2 ⋅ 2
85 simpr ⊢ A ∈ ℤ ∧ 2 ⋅ 2 ≤ 2 ⁢ A → 2 ⋅ 2 ≤ 2 ⁢ A
86 74 78 80 84 85 letrd ⊢ A ∈ ℤ ∧ 2 ⋅ 2 ≤ 2 ⁢ A → 1 ≤ 2 ⁢ A
87 73 86 sylbida ⊢ A ∈ ℤ ∧ 2 ≤ A → 1 ≤ 2 ⁢ A
88 87 3adant1 ⊢ 2 ∈ ℤ ∧ A ∈ ℤ ∧ 2 ≤ A → 1 ≤ 2 ⁢ A
89 42 88 sylbi ⊢ A ∈ ℤ ≥ 2 → 1 ≤ 2 ⁢ A
90 89 3ad2ant1 ⊢ A ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ A < N → 1 ≤ 2 ⁢ A
91 31 90 sylbi ⊢ A ∈ 2 ..^ N → 1 ≤ 2 ⁢ A
92 91 3ad2ant2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 1 ≤ 2 ⁢ A
93 eluz2 ⊢ 2 ⁢ A ∈ ℤ ≥ 1 ↔ 1 ∈ ℤ ∧ 2 ⁢ A ∈ ℤ ∧ 1 ≤ 2 ⁢ A
94 67 70 92 93 syl3anbrc ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 2 ⁢ A ∈ ℤ ≥ 1
95 zsqcl ⊢ A ∈ ℤ → A 2 ∈ ℤ
96 3 95 syl ⊢ A ∈ 2 ..^ N → A 2 ∈ ℤ
97 96 3ad2ant2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → A 2 ∈ ℤ
98 3z ⊢ 3 ∈ ℤ
99 98 a1i ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 3 ∈ ℤ
100 3 3ad2ant2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → A ∈ ℤ
101 nprmdvdsfacm1lem2 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 3 ≤ A
102 eluz2 ⊢ A ∈ ℤ ≥ 3 ↔ 3 ∈ ℤ ∧ A ∈ ℤ ∧ 3 ≤ A
103 99 100 101 102 syl3anbrc ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → A ∈ ℤ ≥ 3
104 2timesltsq ⊢ A ∈ ℤ ≥ 3 → 2 ⁢ A < A 2
105 103 104 syl ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 2 ⁢ A < A 2
106 94 97 105 elfzod ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 2 ⁢ A ∈ 1 ..^ A 2
107 oveq2 ⊢ N = A 2 → 1 ..^ N = 1 ..^ A 2
108 107 eleq2d ⊢ N = A 2 → 2 ⁢ A ∈ 1 ..^ N ↔ 2 ⁢ A ∈ 1 ..^ A 2
109 108 3ad2ant3 ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 2 ⁢ A ∈ 1 ..^ N ↔ 2 ⁢ A ∈ 1 ..^ A 2
110 106 109 mpbird ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → 2 ⁢ A ∈ 1 ..^ N
111 muldvdsfacm1 ⊢ A ∈ 1 ..^ 2 ⁢ A ∧ 2 ⁢ A ∈ 1 ..^ N → A ⁢ 2 ⁢ A ∥ N − 1 !
112 66 110 111 syl2anc ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → A ⁢ 2 ⁢ A ∥ N − 1 !
113 2 10 29 30 112 dvdstrd ⊢ N ∈ ℤ ≥ 6 ∧ A ∈ 2 ..^ N ∧ N = A 2 → N ∥ N − 1 !