PA003V

succ_injective

Stable checked-use theorem · independently closed

Successor is injective (the reusable PA2 lemma).

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 m. S n = S m -> n = m

Structural proof guide

Generated structural guide

Successor is injective (the reusable PA2 lemma).

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

The proof proceeds by direct introduction and elimination.

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

1 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.

01Use earlier factsL1–1

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

  1. L1
    apply PA2

Library-wide reading audit

Original exact command ledger · 1 lines
  1. 0001apply PA2