Metamath Proof Explorer


Theorem zplusmodne

Description: A nonnegative integer is not itself plus a positive integer modulo an integer greater than 1 and the positive integer. (Contributed by AV, 6-Sep-2025)

Ref Expression
Assertion zplusmodne ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → A + K mod N ≠ A mod N

Proof

Step Hyp Ref Expression
1 eluz2nn ⊢ N ∈ ℤ ≥ 2 → N ∈ ℕ
2 1 3ad2ant1 ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → N ∈ ℕ
3 simp2 ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → A ∈ ℤ
4 elfzoelz ⊢ K ∈ 1 ..^ N → K ∈ ℤ
5 4 3ad2ant3 ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → K ∈ ℤ
6 3 5 zaddcld ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → A + K ∈ ℤ
7 3 zcnd ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → A ∈ ℂ
8 4 zcnd ⊢ K ∈ 1 ..^ N → K ∈ ℂ
9 8 3ad2ant3 ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → K ∈ ℂ
10 7 9 pncan2d ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → A + K - A = K
11 elfzo1 ⊢ K ∈ 1 ..^ N ↔ K ∈ ℕ ∧ N ∈ ℕ ∧ K < N
12 nnge1 ⊢ K ∈ ℕ → 1 ≤ K
13 12 anim1i ⊢ K ∈ ℕ ∧ K < N → 1 ≤ K ∧ K < N
14 13 3adant2 ⊢ K ∈ ℕ ∧ N ∈ ℕ ∧ K < N → 1 ≤ K ∧ K < N
15 11 14 sylbi ⊢ K ∈ 1 ..^ N → 1 ≤ K ∧ K < N
16 15 3ad2ant3 ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → 1 ≤ K ∧ K < N
17 16 adantr ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N ∧ A + K - A = K → 1 ≤ K ∧ K < N
18 breq2 ⊢ A + K - A = K → 1 ≤ A + K - A ↔ 1 ≤ K
19 18 adantl ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N ∧ A + K - A = K → 1 ≤ A + K - A ↔ 1 ≤ K
20 breq1 ⊢ A + K - A = K → A + K - A < N ↔ K < N
21 20 adantl ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N ∧ A + K - A = K → A + K - A < N ↔ K < N
22 19 21 anbi12d ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N ∧ A + K - A = K → 1 ≤ A + K - A ∧ A + K - A < N ↔ 1 ≤ K ∧ K < N
23 17 22 mpbird ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N ∧ A + K - A = K → 1 ≤ A + K - A ∧ A + K - A < N
24 10 23 mpdan ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → 1 ≤ A + K - A ∧ A + K - A < N
25 difltmodne ⊢ N ∈ ℕ ∧ A + K ∈ ℤ ∧ A ∈ ℤ ∧ 1 ≤ A + K - A ∧ A + K - A < N → A + K mod N ≠ A mod N
26 2 6 3 24 25 syl121anc ⊢ N ∈ ℤ ≥ 2 ∧ A ∈ ℤ ∧ K ∈ 1 ..^ N → A + K mod N ≠ A mod N