TS002J · theorem body

beta_two_square_prefix_drop_last

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

Restricting a successor-length prefix preserves every witnessed two-square factor representation.

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

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. (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)) -> (forall ftsf_index_drop_old ftsf_factor_drop_old. (exists ftsf_gap_drop_old_bound. ftsf_gap_drop_old_bound + S ftsf_index_drop_old = (l)) -> (((exists ff_h_ftsf_drop_old_entry. ff_h_ftsf_drop_old_entry + S (ftsf_factor_drop_old) = S ((S (ftsf_index_drop_old)) * c)) /\ exists ff_q_ftsf_drop_old_entry. b = ff_q_ftsf_drop_old_entry * S ((S (ftsf_index_drop_old)) * c) + (ftsf_factor_drop_old))) -> (exists ftsf_first_drop_old_representation ftsf_second_drop_old_representation. (ftsf_factor_drop_old) = ftsf_first_drop_old_representation * ftsf_first_drop_old_representation + ftsf_second_drop_old_representation * ftsf_second_drop_old_representation))

Proof neighborhood

Direct theorem prerequisites

le_succ · 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

16 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 assumptionsL1–8

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 hprefix
  5. L5
    intro i
  6. L6
    intro a
  7. L7
    intro hi
  8. L8
    intro ha
02Use earlier factsL9–16

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

  1. L9
    specialize hprefix i
  2. L10
    specialize hprefix a
  3. L11
    apply hprefix
  4. L12
    specialize le_succ (S i)
  5. L13
    specialize le_succ l
  6. L14
    apply le_succ
  7. L15
    exact hi
  8. L16
    exact ha

Library-wide reading audit

Original defined command ledger · 16 lines
  1. 0001intro b
  2. 0002intro c
  3. 0003intro l
  4. 0004intro hprefix
  5. 0005intro i
  6. 0006intro a
  7. 0007intro hi
  8. 0008intro ha
  9. 0009specialize hprefix i
  10. 0010specialize hprefix a
  11. 0011apply hprefix
  12. 0012specialize le_succ (S i)
  13. 0013specialize le_succ l
  14. 0014apply le_succ
  15. 0015exact hi
  16. 0016exact ha