PA000M

one_mul

Stable checked-use theorem · independently closed

One is a left identity for multiplication.

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. 1 * n = n

Structural proof guide

Generated structural guide

One is a left identity for multiplication.

This root lemma is proved directly from the PA rules and the hypotheses introduced by its statement.

The proof proceeds by structural induction (1), certified simplification (2).

Referenced ingredients

none

Proof neighborhood

Direct dependencies

none

Direct dependents

Formal native tactic body

Dependencies are introduced as named hypotheses before line 1. Linked names are exact direct references. This Stable checked-use theorem is independently kernel-checked when replayed.

Read the argument

Proof checkpoints

3 script commands · 1 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.

01Induction on nL1–3

Split the argument into the base and successor obligations. The induction hypothesis is available only in the successor branch.

  1. L1
    induction n
  2. L2
    simp
  3. L3
    simp [IH]

Library-wide reading audit

Original exact command ledger · 3 lines
  1. 0001induction n
  2. 0002simp
  3. 0003simp [IH]