PA00CH · theorem

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.

Statement with defined notation

∀ n. Even(n)ModEq(2,n,0)

Every purple notation token opens its conservative definition. This is a reading surface; the compiler expands the statement before the unchanged kernel checks it.

Definitions used by this theorem

In the theorem statement

2 occurrences

In local proof propositions

none

0 occurrences

Exact expanded native-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)

Proof neighborhood

Direct theorem prerequisites

Direct theorem dependents

Definition-aware tactic body

Only local propositions introduced by have or suffices are compacted. The untrusted compiler re-expands each one before the original tactic script is replayed; defined notation is never accepted by the kernel. Open the exact replay line beneath every changed command.

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.

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 assumptionsL1–2

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 defined 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