This lesson introduces the content types that a Mathematical ASR adds to the general type vocabulary. After completing it, you should be able to identify which type a mathematical page should have and what relations it needs.

The general types are not enough

The general ASR defines types like term and concept. A page typed term could define a species name, a cooking technique, or a mathematical structure — the ASR treats them identically. This is fine for organizing a general-purpose vault, but it means the system cannot distinguish a definition (which needs formal context) from an axiom (which must not claim proof) from a theorem (which must have proof).

Mathematical content types add this distinction. They exist because mathematical validity is constitutive: the relations a page has determine what it IS, not just what it links to.

The validity principle: provability

Mathematical knowledge is valid when it is grounded — traceable through proofs and definitions to accepted starting points (axioms). The dependency graph is a directed acyclic graph: no cycles allowed. If A requires B and B requires A, something is wrong.

This is different from philosophical knowledge, where cycles (claim → argument → objection → response → revised claim) are expected and healthy.

The types

Foundational types

definition — establishes what a term means. MUST have defines:. A definition of “group” that does not specify what “set” and “binary operation” mean (either inline or via requires:) is ambiguous.

axiom — a proposition taken as given. MUST have part-of: (which theory does it belong to?). MUST NOT have proven-by: (axioms are starting points, not conclusions).

Result types

theorem — a proven proposition. MUST have proven-by: linking to a proof. Without proof, it is a conjecture, regardless of what the type: field says.

lemma — same as theorem, but auxiliary. SHOULD have supports: linking to the theorem it serves.

proposition — same as theorem, intermediate significance.

corollary — follows readily from a theorem. MUST have follows-from:.

conjecture — believed true, not yet proven. MUST NOT have proven-by:. If proven, reclassify as theorem.

Proof type

proof — demonstrates a result. MUST have proves: (exactly one target) and uses: (what it relies on). SHOULD have technique: (direct, contradiction, induction, etc.).

Instance types

example — concrete illustration. MUST have illustrates:.

counterexample — concrete refutation. MUST have refutes:.

Check for understanding

Given a page about the commutativity of addition on natural numbers:

  1. What type should it be? (It states a property and proves it → theorem)
  2. What MUST relations does it need? (proven-by: linking to a proof, requires: listing natural numbers and addition)
  3. If no proof exists yet, what type should it be instead? (conjecture)

Given a page defining “prime number”:

  1. What type should it be? (definition)
  2. What MUST relations does it need? (defines: ["prime number"])
  3. What SHOULD relations would strengthen it? (requires: linking to natural numbers and divisibility, has-example: linking to an example of a prime)

Key takeaway

The type determines the obligations. If you cannot satisfy a type’s MUST requirements, either the type is wrong or the page is incomplete. This is not a filing system — it is a validity system.