A ''production system'' describes a set of condition-action rules
to be applied in given situations. At the simplest level this could
just be a set of if-then commands, but usually implies a more complicated
arrangement such as that employed in [Expert System] shells such as
[CLIPS] which do pattern-matching and [unification] of pre-conditions
written in a [predicate logic]-like language over a database of facts.
[CLIPS] is a forward-chaining production system, whereas [Prolog] is a
form of backward-chaining production system (i.e., it tries to reason
backwards from a goal to find facts that support it, rather than reasoning
from known facts to find their consequences).

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[[ [Category Concept] | [Category AI] ]]