Alphabeta Math
TheoremStatement: Literature-sourcedProof: 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.

The principle of mathematical induction

Statement

Let S⊆N. If 0∈S and σ(n)∈S whenever n∈S, then S=N. Equivalently (property form): if a property P satisfies P(0) and (P(n)⇒P(σ(n))) for all n, then P(n) holds for all n∈N. This is the induction principle, the basis of proof by induction.

Facts & Assumptions

Given: N=ω is the smallest inductive set (Inductive set, The natural numbers N (von Neumann), The natural numbers exist: a smallest inductive set); 0=∅, σ(n)=n∪{n}.

[L1]

ω is contained in every inductive set (The natural numbers exist: a smallest inductive set).

Proof

technique · direct
1.1

Suppose S⊆N with 0=∅∈S and (x∈S⇒σ(x)=x∪{x}∈S).

given
2.1

Then S contains ∅ and is closed under x↦x∪{x}, so S is an inductive set.

step 1.1
3.1

N=ω⊆S because ω is a subset of every inductive set.

L1step 2.1
4.1

With S⊆N by hypothesis, S=N.

step 3.1given
5.1

The property form is the set case with S={n∈N:P(n)}: P(0) and P(n)⇒P(σ(n)) give 0∈S and σ-closure, so S=N, i.e. P holds for all n; conversely the set form is the property form applied to P(n):≡n∈S, so the two are equivalent.

step 4.1∎

Depends on

Used by

…and 296 more results.

Dependency tree · two levels

10 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