The Howdy Glossary

Guarded Horn Clauses (GHC) is an extension of Prolog, a logic programming language. GHC uses guarded rules to implement non-deterministic choice and can efficiently model concurrent systems with synchronization primitives. The language was proposed by Krzysztof R. Apt in 1984 as an approach to formal verification and analysis methods for computer programs, combining logical reasoning with the declarative nature of Prolog. Guarded Horn Clauses let developers describe complex relationships between system components without explicitly specifying control flow details or making use of explicit state transitions.