FS005R

four_square_signed_mod_zero_swap

Alpha v34 independently verified · alpha_closed; checked-use authorized; not Stable

Swapping the two summands of a modular zero balance preserves that balance.

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.

Exact expanded first-order arithmetic statement

forall k a b. (exists ftcn_left_fssq_zero_swap_source ftcn_right_fssq_zero_swap_source. (a + b) + (k) * ftcn_left_fssq_zero_swap_source = (0) + (k) * ftcn_right_fssq_zero_swap_source) -> (exists ftcn_left_fssq_zero_swap_result ftcn_right_fssq_zero_swap_result. (b + a) + (k) * ftcn_left_fssq_zero_swap_result = (0) + (k) * ftcn_right_fssq_zero_swap_result)

Constructive proof overview

Generated structural guide

Swapping the two summands of a modular zero balance preserves that balance.

The unchanged tactic script uses 1 declared prerequisite and contains 8 exact native proof lines.

dependency-curried kernel-checked theorem body; Alpha enrollment and checked-use authority follow separately sealed release evidence; Stable membership remains unchanged

Historical empty-context replay experiment only; that experiment persisted no certificate and granted no release authority. Current checked use follows separately sealed, independently verified proof bundles; there is no Stable promotion.

Proof neighborhood

Direct dependencies

add_comm Stable theorem; checked-use authorized

Direct dependents

Formal native tactic body

Dependencies are introduced as named hypotheses before line 1. Local theorem links identify exact declared prerequisites. This exact body belongs to a complete independently kernel-checked constructive proof bundle and has Alpha checked-use authority; it does not imply Stable membership.

Read the argument

Proof checkpoints

8 script commands · 2 reading checkpoints · 1 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.

01Fix variables and assumptionsL1–4

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 hsum
02Establish hswapL5–8

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

  1. L5
    have hswap : a + b = b + a
  2. L6
    apply add_comm
  3. L7
    rewrite hswap at hsum
  4. L8
    exact hsum

Library-wide reading audit

Original exact command ledger · 8 lines
  1. 0001intro k
  2. 0002intro a
  3. 0003intro b
  4. 0004intro hsum
  5. 0005have hswap : a + b = b + a
  6. 0006apply add_comm
  7. 0007rewrite hswap at hsum
  8. 0008exact hsum