Inference engine with conflict resolution based upon the availability of a resource

An inference system used for a process system having a resource, comprising:

• rule storing means for categorizing a plurality of production rules, each of which is comprised of a pair of an "if statement" and a "then statement", as a plurality of groups depending on the amount of cost required for the comparison and for storing the categorized production rule groups;
• fact information storing means for storing fact information;
• condition comparing means for comparing said "if statement" of each production rule of each group stored in said rule storing means with said fact information stored in said fact information storing means selectively to obtain at least one production rule with said "if statement" being satisfied, each group being selected based on the amount of cost required for the comparison, the group having the least comparison cost being selected first;
• conflict resolution means for selecting one of said at least one production rule obtained as the result of the comparison by said condition comparing means;
• and
• rule executing means for executing said "then statement" of said production rule selected by said conflict resolving means.

An inference system used for a process system having a resource, comprising:

• rule storing means for categorizing a plurality of production rules, each of which is comprised of a pair of an "if statement" and a "then statement", as a plurality of groups depending on the amount of cost required for the comparison and for storing the categorized production rule groups;
• fact information storing means for storing fact information;
• condition comparing means for comparing said "if statement" of each production rule of each group stored in said rule storing means with said fact information stored in said fact information storing means selectively based on the availability of the resource of the process system to obtain at least one production rule with said "if statement" being satisfied, each group being selected based on the amount of cost required for the comparison, the group having the least comparison cost being selected first, said comparing continuing successively when said resource is available;
• conflict resolving means for selecting one of said at least one production rule obtained as the result of the comparison by said condition comparing means based on the availability of the resource of the process system, said selecting occurring when said resource becomes unavailable;
• and
• rule executing means for executing said "then statement" of said production rule selected by said conflict resolving means.