A production sYstem consists of a collection of productions (rules), a working memorY of facts and an algorithm, known as forward chaining, for producing new facts from old. A rule becomes eligible to "fire" when its conditions match some set of elements currentlY in working memorY. A conflict resolution strategY determines which of several eligible rules (the conflict set) fires next. A condition is a list of sYmbols which represent constants, which must be matched exactlY variables which bind to the thing theY match and "<> sYmbol" which matches a field not equal to sYmbol. Example production sYstems are OPS5, CLIPS, flex. (2005-06-17)
