definite clause

definite clause (plural definite clauses)

1. (logic) A Horn clause with exactly one positive literal.

   The clauses ${\displaystyle \neg p\vee q}$, ${\displaystyle \neg p\vee \neg q\vee r}$, and ${\displaystyle \neg p\vee \neg q\vee \neg r\vee s}$ are examples of definite clauses. At least in classical logic these would be equivalent to the formulae ${\displaystyle p\rightarrow q}$, ${\displaystyle (p\wedge q)\rightarrow r}$, and ${\displaystyle (p\wedge q\wedge r)\rightarrow s}$, respectively.