Flatfile Agential Resource System Describes

What this is

describes is the aboutness relation — a binary relation between a document and a concept declaring that the document contains content informative about the concept.

The mathematical invariant comes from information science and relevance theory. Aboutness (Maron 1977; Hutchins 1977) is the relation that holds between a document D and a subject S when D contains propositional content that reduces uncertainty about S — when reading D makes a reasoner better informed about S than before. Formally: D aboutness S iff there exists a set of sentences Φ_S ⊆ content(D) such that Φ_S is informative about S (increases the probability of correct answers to questions about S).

This is distinct from and weaker than definition:

• defines: X is a partial function from concepts to files — at most one file is the canonical definition of X. The definer is the authoritative source; the CamelCase name X refers to this file.
• describes: X is a many-to-many relation — many files may describe the same concept, and one file may describe many concepts. No uniqueness constraint. No authoritativeness claim.

Formally: defines ⊆ Files ×₁ Concepts (a partial injection) while describes ⊆ Files × Concepts (an arbitrary binary relation).

The relation is not reflexive in a useful sense (a file about X trivially satisfies any sufficiently weak aboutness criterion). It is not antisymmetric (two files can mutually describe each other). It is not transitive (D describes X, X describes Y does not imply D describes Y — the chain is not guaranteed informative).

When to use describes vs. defines

A file carries describes: X when it contains substantive content about X — discussion, characterization, derivation, worked examples — without claiming to be the canonical specification of X. X may already have a definer elsewhere, or may not yet have one.

A file MUST NOT carry describes: X for concepts it merely mentions. The aboutness relation requires genuine propositional content, not incidental reference.

Open questions

• Whether the set of describes relations should be systematically maintained or is advisory only.
• Whether describes is transitive along chains of increasing specificity — a speculative property that would require a formal treatment of the aboutness lattice.