FS005P · theorem body

four_square_signed_mod_zero_add

Alpha v34 checked-use · independently kernel and Lean verified; not Stable

Two independently vanishing signed blocks have vanishing sum modulo the multiplier.

historical independently replay-verified empty-context experiment; the experiment itself persisted no certificate and granted no release authority; current checked use follows separately sealed proof bundles; no Stable promotion.

Current library: Alpha v34, 4,223 checked-use theorems; Stable remains 432. Historical first admissions, original proof editions, and non-admitted aliases are preserved. Exact original first-admission records.

Statement with defined notation

∀ k. ∀ a. ∀ b. ModEq(k,a,0)ModEq(k,b,0)ModEq(k,a + b,0)

Every purple notation token opens its conservative definition. This reading surface never changes the unchanged intuitionistic kernel or confers checked-use authority.

Definitions used by this theorem

In the theorem statement

In local proof propositions

Exact expanded first-order statement
forall k a b. (exists ftcn_left_fssq_zero_add_left ftcn_right_fssq_zero_add_left. (a) + (k) * ftcn_left_fssq_zero_add_left = (0) + (k) * ftcn_right_fssq_zero_add_left) -> (exists ftcn_left_fssq_zero_add_right ftcn_right_fssq_zero_add_right. (b) + (k) * ftcn_left_fssq_zero_add_right = (0) + (k) * ftcn_right_fssq_zero_add_right) -> (exists ftcn_left_fssq_zero_add_result ftcn_right_fssq_zero_add_result. (a + b) + (k) * ftcn_left_fssq_zero_add_result = (0) + (k) * ftcn_right_fssq_zero_add_result)

Proof neighborhood

Direct theorem prerequisites

mod_eq_add · Stable closed zero_add · Stable closed

Direct theorem dependents

Definition-aware tactic body

Only propositions whose conservative expansion has been checked for exact first-order equivalence are compacted. Every changed line retains its immutable exact replay command.

Read the argument

Proof checkpoints

18 script commands · 3 reading checkpoints · 2 local claims

This is a reading aid, not a new proof or a proof-tree certificate. Checkpoint groups are consecutive commands, not inferred branch boundaries. Every step links to the preserved script.

Definition notation is shown below. Open the paired exact edition for the original native formulas. Source pairing is not a new equivalence certificate.

01Fix variables and assumptionsL1–5

Work with arbitrary variables or the premises of the current implication.

  1. L1
    intro k
  2. L2
    intro a
  3. L3
    intro b
  4. L4
    intro ha
  5. L5
    intro hb
02Establish hsumL6–14

Establish this local claim before using it. It is not an additional assumption. The following proof commands apply mod eq add.

  1. L6
    have hsum : ModEq(k,a + b,0 + 0)Definitions: ModEq(k,a + b,0 + 0)Original native command in the exact edition
  2. L7
    specialize mod_eq_add k
  3. L8
    specialize mod_eq_add a
  4. L9
    specialize mod_eq_add 0
  5. L10
    specialize mod_eq_add b
  6. L11
    specialize mod_eq_add 0
  7. L12
    apply mod_eq_add
  8. L13
    exact ha
  9. L14
    exact hb
03Establish hzeroL15–18

Establish this local claim before using it. It is not an additional assumption. The following proof commands apply zero add.

  1. L15
    have hzero : 0 + 0 = 0
  2. L16
    apply zero_add
  3. L17
    rewrite hzero at hsum
  4. L18
    exact hsum

Library-wide reading audit

Original defined command ledger · 18 lines
  1. 0001intro k
  2. 0002intro a
  3. 0003intro b
  4. 0004intro ha
  5. 0005intro hb
  6. 0006have hsum : ModEq(k,a + b,0 + 0)
    Exact native replay linehave hsum : exists ftcn_left_fssq_zero_add_sum ftcn_right_fssq_zero_add_sum. (a + b) + (k) * ftcn_left_fssq_zero_add_sum = (0 + 0) + (k) * ftcn_right_fssq_zero_add_sum
  7. 0007specialize mod_eq_add k
  8. 0008specialize mod_eq_add a
  9. 0009specialize mod_eq_add 0
  10. 0010specialize mod_eq_add b
  11. 0011specialize mod_eq_add 0
  12. 0012apply mod_eq_add
  13. 0013exact ha
  14. 0014exact hb
  15. 0015have hzero : 0 + 0 = 0
  16. 0016apply zero_add
  17. 0017rewrite hzero at hsum
  18. 0018exact hsum