Horn Clause

Definitions

1. A logical formula consisting of a disjunction of literals with at most one positive literal, forming the basis of logic programming languages like Prolog. A definite Horn clause has exactly one positive literal and represents an implication rule.

   In plain English: A simple logical rule saying 'if all these conditions are true, then this conclusion follows' — the fundamental building block of Prolog programs.

   Example: "Prolog programs are essentially collections of Horn clauses that the engine resolves through unification and backtracking."

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