Rule Interpreter(forward chaining Identify triggered rules, creating rule instances triggered rule antecedents in assertions database can change the database(e.g. add new assertion) rule instance: rule with variables filled in Choose one rule instance(called conflict resolution) Conflict resolution strategies e.g. first instance, random instance Fire the chosen rule instance Firing a rule instance means performing the actions ndicated by the rule (e.g. adding a new assertion) Terminate when no triggered rules or special stop assertion Forward chaining-strep throat (using rule order for conflict resolution) 1:主f hroat infec)) ococcus) then (sages tthat at infec) R4: if R2: if stain gram-pos) red throat then (signs (throat infec)) morph chain Asserti。ns: (sore throat (。 rg stain gram-pos) org morph coccus)10 Rule Interpreter (forward chaining) • Identify triggered rules, creating rule instances • triggered rule: – antecedents in assertions database – can change the database (e.g. add new assertion) • rule instance: rule with variables filled in • Choose one rule instance (called conflict resolution) • Conflict resolution strategies e.g. first instance, random instance, etc. • Fire the chosen rule instance • Firing a rule instance means performing the actions indicated by the rule – (e.g. adding a new assertion) • Terminate when no triggered rules or special stop assertion Forward chaining - strep throat (using rule order for conflict resolution) R1: if (signs (throat infec)) (org streptococcus) then (strep throat) R2: if (red throat) then (signs (throat infec)) R3: if (sore throat) then (signs (throat infec)) R4: if (org stain gram-pos) (org morph coccus) (org growth chains) then (org streptococcus) Assertions: (sore throat) (org stain gram-pos) (org morph coccus) (org growth chains)