PA003F · theorem

zero_le

Stable checked-use theorem · independently closed

Zero is below every natural number.

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. Le(0,n)

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

1 occurrences

In local proof propositions

none

0 occurrences

Exact expanded native-PA statement
forall n. 0 <= n

Proof neighborhood

Direct theorem prerequisites

none

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

4 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.

Definition notation is shown below. Open the paired exact edition for the original native formulas. Source pairing is not a new equivalence certificate.

01Fix variables and assumptionsL1–1

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

  1. L1
    intro n
02Construct an explicit witnessL2–2

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

  1. L2
    exists n
03Calculate and transport equalitiesL3–4

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

  1. L3
    rewrite PA3
  2. L4
    refl

Library-wide reading audit

Original defined command ledger · 4 lines
  1. 0001intro n
  2. 0002exists n
  3. 0003rewrite PA3
  4. 0004refl