BL0002

binary_length_digit_split_exists

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

Every natural number has an exact binary quotient and zero-or-one digit.

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 n. exists h b. ((((b = 0) \/ (b = 1)) /\ n = (h + h) + b))

Constructive proof overview

Generated structural guide

Every natural number has an exact binary quotient and zero-or-one digit.

The unchanged tactic script uses 1 declared prerequisite and contains 3 exact native proof lines.

Alpha v34 checked-use · first admitted v22 · independently kernel and Lean verified; not Stable

Proof neighborhood

Direct dependencies

binary_exponent_split_exists Alpha 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

3 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.

01Fix variables and assumptionsL1–1

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

  1. L1
    intro n
02Use earlier factsL2–3

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

  1. L2
    specialize binary_exponent_split_exists n
  2. L3
    exact binary_exponent_split_exists

Library-wide reading audit

Original exact command ledger · 3 lines
  1. 0001intro n
  2. 0002specialize binary_exponent_split_exists n
  3. 0003exact binary_exponent_split_exists