sequencing the application of rules
a rule-based system has
- a set of rules, often very large
- heuristics that determine which order to apply the rules in
which rule is applied first?
are rules applied repeatedly?
partial matches
- rules may be applied against part of the input
- for example, in arithmetic simplification want to reduce (x + x) to 2x whatever context it appears in
- so (y + x + x) should be simplified to (y + 2x)