Languages / Knowledge library
Prolog
facts rules unification and backtracking
Why learn Prolog?
Useful when a problem is naturally relational or rule-based. Goal ordering and termination behavior matter even in declarative programs.
Where it came from
Prolog expresses programs through facts, rules, and queries. Implementations such as SWI-Prolog provide execution environments for logical inference and search.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Declare facts about a small graph.
- Write a rule for a derived relationship.
- Query for multiple valid solutions.
- Trace unification and backtracking.
- Test recursive rules for termination on cyclic input.
Documentation and sources
- Official project documentation (www.swi-prolog.org)
Catalog research notes
- Research snapshot: September 9, 2026. This entry summarizes the linked primary documentation; it does not assert a latest release version.