BT0081 · Bertrand theorem

pow_zero

Stable checked-use theorem · independently kernel verified

The relational zeroth power 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.

Statement with defined notation

∀ a. ∀ e. ∀ n. e = 0 → Pow(a,e,n) → n = 1

Every purple notation token opens its conservative definition. Expanding the displayed statement recovers the exact first-order Peano-arithmetic formula checked by the unchanged kernel.

Definitions used by this theorem

In the theorem statement

1 occurrences

In local proof propositions

none

0 occurrences

Exact expanded native-PA statement
forall a e n. e = 0 -> (exists ff_b_z ff_c_z. ((forall ff_i_z_repeat. (exists ff_lt_z_repeat_bound. ff_lt_z_repeat_bound + S ff_i_z_repeat = e) -> (((exists ff_h_z_repeat_decoded. ff_h_z_repeat_decoded + S (a) = S ((S (ff_i_z_repeat)) * ff_c_z)) /\ exists ff_q_z_repeat_decoded. ff_b_z = ff_q_z_repeat_decoded * S ((S (ff_i_z_repeat)) * ff_c_z) + (a)))) /\ (exists ff_u_z_product ff_v_z_product. ((((exists ff_h_z_product_start. ff_h_z_product_start + S (1) = S ((S (0)) * ff_v_z_product)) /\ exists ff_q_z_product_start. ff_u_z_product = ff_q_z_product_start * S ((S (0)) * ff_v_z_product) + (1))) /\ ((((exists ff_h_z_product_terminal. ff_h_z_product_terminal + S (n) = S ((S (e)) * ff_v_z_product)) /\ exists ff_q_z_product_terminal. ff_u_z_product = ff_q_z_product_terminal * S ((S (e)) * ff_v_z_product) + (n))) /\ forall ff_i_z_product. (exists ff_lt_z_product_bound. ff_lt_z_product_bound + S ff_i_z_product = e) -> exists ff_p_z_product ff_r_z_product ff_s_z_product. ((((exists ff_h_z_product_factor. ff_h_z_product_factor + S (ff_p_z_product) = S ((S (ff_i_z_product)) * ff_c_z)) /\ exists ff_q_z_product_factor. ff_b_z = ff_q_z_product_factor * S ((S (ff_i_z_product)) * ff_c_z) + (ff_p_z_product))) /\ ((((exists ff_h_z_product_partial. ff_h_z_product_partial + S (ff_r_z_product) = S ((S (ff_i_z_product)) * ff_v_z_product)) /\ exists ff_q_z_product_partial. ff_u_z_product = ff_q_z_product_partial * S ((S (ff_i_z_product)) * ff_v_z_product) + (ff_r_z_product))) /\ ((((exists ff_h_z_product_successor. ff_h_z_product_successor + S (ff_s_z_product) = S ((S (S ff_i_z_product)) * ff_v_z_product)) /\ exists ff_q_z_product_successor. ff_u_z_product = ff_q_z_product_successor * S ((S (S ff_i_z_product)) * ff_v_z_product) + (ff_s_z_product))) /\ ff_s_z_product = ff_r_z_product * ff_p_z_product)))))))) -> n = 1

Proof neighborhood

Direct theorem prerequisites

Direct theorem dependents

Definition-aware tactic body

Only local propositions introduced by have or suffices are compacted. Every changed line has an exact-AST conservative-expansion receipt; the kernel still receives the immutable original tactic script.

Read the argument

Proof checkpoints

17 script commands · 4 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 (1)
01Fix variables and assumptionsL1–5

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

  1. L1
    intro a
  2. L2
    intro e
  3. L3
    intro n
  4. L4
    intro he
  5. L5
    intro hpow
02Calculate and transport equalitiesL6–9

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

  1. L6
    rewrite he at hpow
  2. L7
    rewrite he at hpow
  3. L8
    rewrite he at hpow
  4. L9
    rewrite he at hpow
03Separate the logical casesL10–12

Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.

  1. L10
    cases hpow
  2. L11
    cases hpow_witness
  3. L12
    cases hpow_witness_witness
04Use earlier factsL13–17

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

  1. L13
    specialize beta_product_zero x
  2. L14
    specialize beta_product_zero x1
  3. L15
    specialize beta_product_zero n
  4. L16
    apply beta_product_zero
  5. L17
    exact hpow_witness_witness_right

Library-wide reading audit

Original defined command ledger · 17 lines
  1. 0001intro a
  2. 0002intro e
  3. 0003intro n
  4. 0004intro he
  5. 0005intro hpow
  6. 0006rewrite he at hpow
  7. 0007rewrite he at hpow
  8. 0008rewrite he at hpow
  9. 0009rewrite he at hpow
  10. 0010cases hpow
  11. 0011cases hpow_witness
  12. 0012cases hpow_witness_witness
  13. 0013specialize beta_product_zero x
  14. 0014specialize beta_product_zero x1
  15. 0015specialize beta_product_zero n
  16. 0016apply beta_product_zero
  17. 0017exact hpow_witness_witness_right