PA00CH

even_to_mod_two_zero

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

Every even natural is congruent to zero 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_even_n. n = 2 * pmt_even_n) -> (exists pmt_u_n_zero pmt_v_n_zero. n + 2 * pmt_u_n_zero = 0 + 2 * pmt_v_n_zero)

Structural proof guide

Generated structural guide

Every even natural is congruent to zero modulo two.

Use the direct prerequisites dvd_to_mod_zero as previously established PA formulas.

The proof proceeds by direct introduction and elimination.

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

6 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.

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 heven
02Use earlier factsL3–6

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

  1. L3
    specialize dvd_to_mod_zero 2
  2. L4
    specialize dvd_to_mod_zero n
  3. L5
    apply dvd_to_mod_zero
  4. L6
    exact heven

Library-wide reading audit

Original exact command ledger · 6 lines
  1. 0001intro n
  2. 0002intro heven
  3. 0003specialize dvd_to_mod_zero 2
  4. 0004specialize dvd_to_mod_zero n
  5. 0005apply dvd_to_mod_zero
  6. 0006exact heven