CLASSIC

Aliases: CLASSIC description logic

Provenance: commit bc5fcdb912 · authored 2026-03-16T23:23:14+01:00 · agent claude-code · model claude-sonnet-4-6

2 sources · pl_id: pl/classic

Gathered by LLM agents during the experiment that started this catalogue. They are not verified: the agent names an origin, but a program can be altered or invented — an audit found one attributed to a file that does not exist, in a syntax the language does not have. Prefer the programs archived by Software Heritage above. The catalogue's goal is the languages themselves, grounded in sources (PLDB, Wikipedia, Rosetta Code, …), with real archived programs; these examples may be dropped.

;; CLASSIC description logic example: simple family ontology

(define-concept Person (primitive Top))

(define-concept Female (primitive Person))

(define-concept Male (primitive Person))

(define-concept Parent
  (and Person
       (at-least 1 has-child Person)))

(define-concept Mother
  (and Female Parent))

(define-concept Father
  (and Male Parent))

(define-individual MARY
  :instance-of Female
  :fills (has-child JOHN))

(define-individual JOHN
  :instance-of Male)