BL0012

binary_length_zero_input_general

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

Any canonical bit-length witness at an input equal to zero is one.

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 l. n = 0 -> ((((n) = 0 /\ (l) = 1) \/ exists ff_exponent_bl_length ff_lower_bl_length ff_upper_bl_length. (((l) = S ff_exponent_bl_length) /\ ((exists ff_positive_bl_length. ff_positive_bl_length + 1 = (n)) /\ ((exists pa_b_bl_length_lower pa_c_bl_length_lower. ((forall pa_i_bl_length_lower_repeat. (exists pa_lt_bl_length_lower_repeat_bound. pa_lt_bl_length_lower_repeat_bound + S pa_i_bl_length_lower_repeat = ff_exponent_bl_length) -> (((exists pa_h_bl_length_lower_repeat_decoded. pa_h_bl_length_lower_repeat_decoded + S (2) = S ((S (pa_i_bl_length_lower_repeat)) * pa_c_bl_length_lower)) /\ exists pa_q_bl_length_lower_repeat_decoded. pa_b_bl_length_lower = pa_q_bl_length_lower_repeat_decoded * S ((S (pa_i_bl_length_lower_repeat)) * pa_c_bl_length_lower) + (2)))) /\ (exists pa_u_bl_length_lower_product pa_v_bl_length_lower_product. ((((exists pa_h_bl_length_lower_product_start. pa_h_bl_length_lower_product_start + S (1) = S ((S (0)) * pa_v_bl_length_lower_product)) /\ exists pa_q_bl_length_lower_product_start. pa_u_bl_length_lower_product = pa_q_bl_length_lower_product_start * S ((S (0)) * pa_v_bl_length_lower_product) + (1))) /\ ((((exists pa_h_bl_length_lower_product_terminal. pa_h_bl_length_lower_product_terminal + S (ff_lower_bl_length) = S ((S (ff_exponent_bl_length)) * pa_v_bl_length_lower_product)) /\ exists pa_q_bl_length_lower_product_terminal. pa_u_bl_length_lower_product = pa_q_bl_length_lower_product_terminal * S ((S (ff_exponent_bl_length)) * pa_v_bl_length_lower_product) + (ff_lower_bl_length))) /\ forall pa_i_bl_length_lower_product. (exists pa_lt_bl_length_lower_product_bound. pa_lt_bl_length_lower_product_bound + S pa_i_bl_length_lower_product = ff_exponent_bl_length) -> exists pa_p_bl_length_lower_product pa_r_bl_length_lower_product pa_s_bl_length_lower_product. ((((exists pa_h_bl_length_lower_product_factor. pa_h_bl_length_lower_product_factor + S (pa_p_bl_length_lower_product) = S ((S (pa_i_bl_length_lower_product)) * pa_c_bl_length_lower)) /\ exists pa_q_bl_length_lower_product_factor. pa_b_bl_length_lower = pa_q_bl_length_lower_product_factor * S ((S (pa_i_bl_length_lower_product)) * pa_c_bl_length_lower) + (pa_p_bl_length_lower_product))) /\ ((((exists pa_h_bl_length_lower_product_partial. pa_h_bl_length_lower_product_partial + S (pa_r_bl_length_lower_product) = S ((S (pa_i_bl_length_lower_product)) * pa_v_bl_length_lower_product)) /\ exists pa_q_bl_length_lower_product_partial. pa_u_bl_length_lower_product = pa_q_bl_length_lower_product_partial * S ((S (pa_i_bl_length_lower_product)) * pa_v_bl_length_lower_product) + (pa_r_bl_length_lower_product))) /\ ((((exists pa_h_bl_length_lower_product_successor. pa_h_bl_length_lower_product_successor + S (pa_s_bl_length_lower_product) = S ((S (S pa_i_bl_length_lower_product)) * pa_v_bl_length_lower_product)) /\ exists pa_q_bl_length_lower_product_successor. pa_u_bl_length_lower_product = pa_q_bl_length_lower_product_successor * S ((S (S pa_i_bl_length_lower_product)) * pa_v_bl_length_lower_product) + (pa_s_bl_length_lower_product))) /\ pa_s_bl_length_lower_product = pa_r_bl_length_lower_product * pa_p_bl_length_lower_product)))))))) /\ ((exists pa_b_bl_length_upper pa_c_bl_length_upper. ((forall pa_i_bl_length_upper_repeat. (exists pa_lt_bl_length_upper_repeat_bound. pa_lt_bl_length_upper_repeat_bound + S pa_i_bl_length_upper_repeat = l) -> (((exists pa_h_bl_length_upper_repeat_decoded. pa_h_bl_length_upper_repeat_decoded + S (2) = S ((S (pa_i_bl_length_upper_repeat)) * pa_c_bl_length_upper)) /\ exists pa_q_bl_length_upper_repeat_decoded. pa_b_bl_length_upper = pa_q_bl_length_upper_repeat_decoded * S ((S (pa_i_bl_length_upper_repeat)) * pa_c_bl_length_upper) + (2)))) /\ (exists pa_u_bl_length_upper_product pa_v_bl_length_upper_product. ((((exists pa_h_bl_length_upper_product_start. pa_h_bl_length_upper_product_start + S (1) = S ((S (0)) * pa_v_bl_length_upper_product)) /\ exists pa_q_bl_length_upper_product_start. pa_u_bl_length_upper_product = pa_q_bl_length_upper_product_start * S ((S (0)) * pa_v_bl_length_upper_product) + (1))) /\ ((((exists pa_h_bl_length_upper_product_terminal. pa_h_bl_length_upper_product_terminal + S (ff_upper_bl_length) = S ((S (l)) * pa_v_bl_length_upper_product)) /\ exists pa_q_bl_length_upper_product_terminal. pa_u_bl_length_upper_product = pa_q_bl_length_upper_product_terminal * S ((S (l)) * pa_v_bl_length_upper_product) + (ff_upper_bl_length))) /\ forall pa_i_bl_length_upper_product. (exists pa_lt_bl_length_upper_product_bound. pa_lt_bl_length_upper_product_bound + S pa_i_bl_length_upper_product = l) -> exists pa_p_bl_length_upper_product pa_r_bl_length_upper_product pa_s_bl_length_upper_product. ((((exists pa_h_bl_length_upper_product_factor. pa_h_bl_length_upper_product_factor + S (pa_p_bl_length_upper_product) = S ((S (pa_i_bl_length_upper_product)) * pa_c_bl_length_upper)) /\ exists pa_q_bl_length_upper_product_factor. pa_b_bl_length_upper = pa_q_bl_length_upper_product_factor * S ((S (pa_i_bl_length_upper_product)) * pa_c_bl_length_upper) + (pa_p_bl_length_upper_product))) /\ ((((exists pa_h_bl_length_upper_product_partial. pa_h_bl_length_upper_product_partial + S (pa_r_bl_length_upper_product) = S ((S (pa_i_bl_length_upper_product)) * pa_v_bl_length_upper_product)) /\ exists pa_q_bl_length_upper_product_partial. pa_u_bl_length_upper_product = pa_q_bl_length_upper_product_partial * S ((S (pa_i_bl_length_upper_product)) * pa_v_bl_length_upper_product) + (pa_r_bl_length_upper_product))) /\ ((((exists pa_h_bl_length_upper_product_successor. pa_h_bl_length_upper_product_successor + S (pa_s_bl_length_upper_product) = S ((S (S pa_i_bl_length_upper_product)) * pa_v_bl_length_upper_product)) /\ exists pa_q_bl_length_upper_product_successor. pa_u_bl_length_upper_product = pa_q_bl_length_upper_product_successor * S ((S (S pa_i_bl_length_upper_product)) * pa_v_bl_length_upper_product) + (pa_s_bl_length_upper_product))) /\ pa_s_bl_length_upper_product = pa_r_bl_length_upper_product * pa_p_bl_length_upper_product)))))))) /\ ((exists ff_lower_gap_bl_length. ff_lower_gap_bl_length + (ff_lower_bl_length) = (n)) /\ (exists ff_upper_gap_bl_length. ff_upper_gap_bl_length + S (n) = (ff_upper_bl_length))))))))) -> l = 1

Constructive proof overview

Generated structural guide

Any canonical bit-length witness at an input equal to zero is one.

The unchanged tactic script uses 1 declared prerequisite and contains 11 exact native proof lines.

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

Proof neighborhood

Direct dependencies

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

11 script commands · 3 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.

Named ingredients (1)
01Fix variables and assumptionsL1–4

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

  1. L1
    intro n
  2. L2
    intro l
  3. L3
    intro hzero
  4. L4
    intro hlength
02Calculate and transport equalitiesL5–8

Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.

  1. L5
    rewrite hzero at hlength
  2. L6
    rewrite hzero at hlength
  3. L7
    rewrite hzero at hlength
  4. L8
    rewrite hzero at hlength
03Use earlier factsL9–11

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

  1. L9
    specialize binary_length_zero_input_value l
  2. L10
    apply binary_length_zero_input_value
  3. L11
    exact hlength

Library-wide reading audit

Original exact command ledger · 11 lines
  1. 0001intro n
  2. 0002intro l
  3. 0003intro hzero
  4. 0004intro hlength
  5. 0005rewrite hzero at hlength
  6. 0006rewrite hzero at hlength
  7. 0007rewrite hzero at hlength
  8. 0008rewrite hzero at hlength
  9. 0009specialize binary_length_zero_input_value l
  10. 0010apply binary_length_zero_input_value
  11. 0011exact hlength