TS002L · theorem body

beta_two_square_prefix_last_represented

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

The final decoded factor of a represented successor prefix has its own explicit two-square witnesses.

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

∀ b. ∀ c. ∀ l. ∀ a. (∀ x. ∀ y. Lt(x,S l)BetaAt(b,c,x,y) → ∃ z. ∃ n. y = z · z + n · n) → BetaAt(b,c,l,a) → ∃ x. ∃ y. a = x · x + y · y

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 b c l a. (forall ftsf_index_drop_next ftsf_factor_drop_next. (exists ftsf_gap_drop_next_bound. ftsf_gap_drop_next_bound + S ftsf_index_drop_next = (S l)) -> (((exists ff_h_ftsf_drop_next_entry. ff_h_ftsf_drop_next_entry + S (ftsf_factor_drop_next) = S ((S (ftsf_index_drop_next)) * c)) /\ exists ff_q_ftsf_drop_next_entry. b = ff_q_ftsf_drop_next_entry * S ((S (ftsf_index_drop_next)) * c) + (ftsf_factor_drop_next))) -> (exists ftsf_first_drop_next_representation ftsf_second_drop_next_representation. (ftsf_factor_drop_next) = ftsf_first_drop_next_representation * ftsf_first_drop_next_representation + ftsf_second_drop_next_representation * ftsf_second_drop_next_representation)) -> (((exists ff_h_ftsf_last_entry. ff_h_ftsf_last_entry + S (a) = S ((S (l)) * c)) /\ exists ff_q_ftsf_last_entry. b = ff_q_ftsf_last_entry * S ((S (l)) * c) + (a))) -> (exists ftsf_first_last_result ftsf_second_last_result. (a) = ftsf_first_last_result * ftsf_first_last_result + ftsf_second_last_result * ftsf_second_last_result)

Proof neighborhood

Direct theorem prerequisites

le_refl · 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

12 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.

01Fix variables and assumptionsL1–6

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

  1. L1
    intro b
  2. L2
    intro c
  3. L3
    intro l
  4. L4
    intro a
  5. L5
    intro hprefix
  6. L6
    intro hlast
02Use earlier factsL7–12

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

  1. L7
    specialize hprefix l
  2. L8
    specialize hprefix a
  3. L9
    apply hprefix
  4. L10
    specialize le_refl (S l)
  5. L11
    exact le_refl
  6. L12
    exact hlast

Library-wide reading audit

Original defined command ledger · 12 lines
  1. 0001intro b
  2. 0002intro c
  3. 0003intro l
  4. 0004intro a
  5. 0005intro hprefix
  6. 0006intro hlast
  7. 0007specialize hprefix l
  8. 0008specialize hprefix a
  9. 0009apply hprefix
  10. 0010specialize le_refl (S l)
  11. 0011exact le_refl
  12. 0012exact hlast