FS003N · theorem body

four_square_lagrange_from_odd_signed_quaternion

dependency-curried kernel-checked candidate body; not enrolled in Alpha or Stable

Universal Lagrange follows constructively from exactly one visible remaining hypothesis: representation of each odd signed centered quaternion quotient.

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

(∀ x. ∀ y. ∀ z. ∀ n. ∀ m. ∀ k. ∀ i. ∀ j. ∀ u. ∀ v. ∀ w. ∀ x0. ¬y = 0 → y = 2 · z + 1 → x · y = n · n + m · m + k · k + i · i → Le(j + j,y) ∧ ((∃ x1. n = y · x1 + j) ∨ Dvd(y,n + j)) → Le(u + u,y) ∧ ((∃ x1. m = y · x1 + u) ∨ Dvd(y,m + u)) → Le(v + v,y) ∧ ((∃ x1. k = y · x1 + v) ∨ Dvd(y,k + v)) → Le(w + w,y) ∧ ((∃ x1. i = y · x1 + w) ∨ Dvd(y,i + w)) → y · x0 = j · j + u · u + v · v + w · w → ∃ x1. ∃ x2. ∃ x3. ∃ x4. x · x0 = x1 · x1 + x2 · x2 + x3 · x3 + x4 · x4) → ∀ x. ∃ y. ∃ z. ∃ n. ∃ m. x = y · y + z · z + n · n + m · m

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

none
Exact expanded first-order statement
(forall fsbr_modulus_final fsbr_multiplier_final fsbr_half_final fsbr_coordinate_final_0 fsbr_coordinate_final_1 fsbr_coordinate_final_2 fsbr_coordinate_final_3 fsbr_center_final_0 fsbr_center_final_1 fsbr_center_final_2 fsbr_center_final_3 fsbr_quotient_final. ~(fsbr_multiplier_final = 0) -> fsbr_multiplier_final = 2 * fsbr_half_final + 1 -> fsbr_modulus_final * fsbr_multiplier_final = fsbr_coordinate_final_0 * fsbr_coordinate_final_0 + fsbr_coordinate_final_1 * fsbr_coordinate_final_1 + fsbr_coordinate_final_2 * fsbr_coordinate_final_2 + fsbr_coordinate_final_3 * fsbr_coordinate_final_3 -> (((exists fsd_center_bound_final_0. fsd_center_bound_final_0 + (fsbr_center_final_0 + fsbr_center_final_0) = fsbr_multiplier_final) /\ ((exists fsd_center_lower_final_0. fsbr_coordinate_final_0 = fsbr_multiplier_final * fsd_center_lower_final_0 + fsbr_center_final_0) \/ (exists fsd_center_upper_final_0. fsbr_coordinate_final_0 + fsbr_center_final_0 = fsbr_multiplier_final * fsd_center_upper_final_0)))) -> (((exists fsd_center_bound_final_1. fsd_center_bound_final_1 + (fsbr_center_final_1 + fsbr_center_final_1) = fsbr_multiplier_final) /\ ((exists fsd_center_lower_final_1. fsbr_coordinate_final_1 = fsbr_multiplier_final * fsd_center_lower_final_1 + fsbr_center_final_1) \/ (exists fsd_center_upper_final_1. fsbr_coordinate_final_1 + fsbr_center_final_1 = fsbr_multiplier_final * fsd_center_upper_final_1)))) -> (((exists fsd_center_bound_final_2. fsd_center_bound_final_2 + (fsbr_center_final_2 + fsbr_center_final_2) = fsbr_multiplier_final) /\ ((exists fsd_center_lower_final_2. fsbr_coordinate_final_2 = fsbr_multiplier_final * fsd_center_lower_final_2 + fsbr_center_final_2) \/ (exists fsd_center_upper_final_2. fsbr_coordinate_final_2 + fsbr_center_final_2 = fsbr_multiplier_final * fsd_center_upper_final_2)))) -> (((exists fsd_center_bound_final_3. fsd_center_bound_final_3 + (fsbr_center_final_3 + fsbr_center_final_3) = fsbr_multiplier_final) /\ ((exists fsd_center_lower_final_3. fsbr_coordinate_final_3 = fsbr_multiplier_final * fsd_center_lower_final_3 + fsbr_center_final_3) \/ (exists fsd_center_upper_final_3. fsbr_coordinate_final_3 + fsbr_center_final_3 = fsbr_multiplier_final * fsd_center_upper_final_3)))) -> fsbr_multiplier_final * fsbr_quotient_final = fsbr_center_final_0 * fsbr_center_final_0 + fsbr_center_final_1 * fsbr_center_final_1 + fsbr_center_final_2 * fsbr_center_final_2 + fsbr_center_final_3 * fsbr_center_final_3 -> (exists fsl_a_fsbr_signed_final fsl_b_fsbr_signed_final fsl_c_fsbr_signed_final fsl_d_fsbr_signed_final. (fsbr_modulus_final * fsbr_quotient_final) = fsl_a_fsbr_signed_final * fsl_a_fsbr_signed_final + fsl_b_fsbr_signed_final * fsl_b_fsbr_signed_final + fsl_c_fsbr_signed_final * fsl_c_fsbr_signed_final + fsl_d_fsbr_signed_final * fsl_d_fsbr_signed_final)) -> forall n. (exists fsl_a_fslf_natural fsl_b_fslf_natural fsl_c_fslf_natural fsl_d_fslf_natural. (n) = fsl_a_fslf_natural * fsl_a_fslf_natural + fsl_b_fslf_natural * fsl_b_fslf_natural + fsl_c_fslf_natural * fsl_c_fslf_natural + fsl_d_fslf_natural * fsl_d_fslf_natural)

Proof neighborhood

Direct theorem prerequisites

Direct theorem dependents

none

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

4 script commands · 2 reading checkpoints · 0 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.

Named ingredients (2)
01Fix variables and assumptionsL1–1

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

  1. L1
    intro hsigned
02Use earlier factsL2–4

Instantiate or apply named facts and discharge the corresponding proof obligations.

  1. L2
    apply four_square_lagrange_from_all_primes
  2. L3
    apply four_square_prime_from_odd_signed_quaternion
  3. L4
    exact hsigned

Library-wide reading audit

Original defined command ledger · 4 lines
  1. 0001intro hsigned
  2. 0002apply four_square_lagrange_from_all_primes
  3. 0003apply four_square_prime_from_odd_signed_quaternion
  4. 0004exact hsigned