Alphabeta Math
TheoremStatement: AI-adaptedProof: AI-adaptedprecheck passverified 2026-08-02 (claude-opus-5)
How statement and proof provenance work

The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.

  • Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
  • AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
  • AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.

These labels describe origin, not correctness: citations and verification chips remain separate evidence.

Strong (complete) induction

Statement

Let P be a property of naturals such that for every n∈N, if P(m) holds for all m<n then P(n). Then P(n) holds for all n∈N. (At n=0 the hypothesis is vacuous, so P(0) is forced.)

Facts & Assumptions

Given: A property P satisfying the strong-induction hypothesis H: for every n, (P(m) for all m<n)⇒P(n).

[L1]

Well-ordering: every nonempty subset of N has a least element (The well-ordering principle).

[L2]

Exactly one of x<y, x=y, y<x holds (Trichotomy of the order on N).

Proof

technique · contradiction
1.1

Suppose P fails somewhere; let S={ n∈N:P(n) is false }, a nonempty subset of N.

assume-contra
2.1

By well-ordering [L1], S has a least element ℓ, so ℓ≤s for every s∈S; hence every m<ℓ lies outside S, since m∈S would give ℓ≤m, which [L2] does not allow alongside m<ℓ; that is, P(m) holds for all m<ℓ.

step 1.1L1L2
3.1

By the hypothesis H applied at ℓ, P(ℓ) holds, so ℓ∉S.

step 2.1given
4.1

But ℓ∈S by construction, a contradiction; hence S is empty and P(n) holds for all n∈N.

step 2.1step 3.1discharge-contradiction∎

Depends on

Used by

Dependency tree · two levels

19 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.

Sources