definite clause

Noun

 * 1)  A Horn clause with exactly one positive literal.
 * The clauses $$ \neg p \vee q $$, $$ \neg p \vee \neg q \vee r $$, and $$ \neg p \vee \neg q \vee \neg r \vee s$$ are examples of definite clauses. At least in classical logic these would be equivalent to the formulae $$p \rightarrow q$$, $$(p \wedge q) \rightarrow r$$, and $$(p \wedge q \wedge r) \rightarrow s$$, respectively.