PA00CI

odd_to_mod_two_one

Alpha v34 checked-use theorem · independently closed; not Stable

Every odd natural is congruent to one modulo two.

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 PA statement

forall n. (exists pmt_odd_n. n = 2 * pmt_odd_n + 1) -> (exists pmt_u_n_one pmt_v_n_one. n + 2 * pmt_u_n_one = 1 + 2 * pmt_v_n_one)

Structural proof guide

Generated structural guide

Every odd natural is congruent to one modulo two.

Use the direct prerequisites add_comm as previously established PA formulas.

The proof proceeds by case analysis (1), equality transport (1), certified simplification (2).

Referenced ingredients

Proof neighborhood

Direct dependencies

Direct dependents

Formal native tactic body

Dependencies are introduced as named hypotheses before line 1. Linked names are exact direct references. This Alpha-v25 checked-use theorem is independently kernel-checked when replayed; it is not a Stable theorem.

Read the argument

Proof checkpoints

11 script commands · 6 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 assumptionsL1–2

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

  1. L1
    intro n
  2. L2
    intro hodd
02Separate the logical casesL3–3

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

  1. L3
    cases hodd
03Construct an explicit witnessL4–5

Supply the displayed value, then prove that it has the required property.

  1. L4
    exists 0
  2. L5
    exists x
04Calculate and transport equalitiesL6–9

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

  1. L6
    rewrite hodd_witness
  2. L7
    simp
  3. L8
    symm
  4. L9
    trans 2 * x + 1
05Use earlier factsL10–10

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

  1. L10
    apply add_comm
06Calculate and transport equalitiesL11–11

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

  1. L11
    simp

Library-wide reading audit

Original exact command ledger · 11 lines
  1. 0001intro n
  2. 0002intro hodd
  3. 0003cases hodd
  4. 0004exists 0
  5. 0005exists x
  6. 0006rewrite hodd_witness
  7. 0007simp
  8. 0008symm
  9. 0009trans 2 * x + 1
  10. 0010apply add_comm
  11. 0011simp