Production system for an expert system

• US 4,937,755 A
• Filed: 04/28/1988
• Issued: 06/26/1990
• Est. Priority Date: 05/06/1987
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yokota, Takayoshi, Bekki, Keisuke, Hamada, Nobuhiro
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Trans, V. N.
• Application Number:
  US07/187,590
• Time in Patent Office: 789 Days
• Field of Search: 364/488-491, 364/513, 364/300, 364/468, 364/200, 364/900
• US Class Current: 700/104
• CPC Class Codes: G06F 30/327 Logic synthesis; Behaviour synthesis, e.g. mapping logic, HDL to netlist, high-level language to RTL or netlist
• CPC Class Codes: G06N 5/01 Dynamic search techniques; Heuristics; Dynamic trees; Branch-and-bound
• CPC Class Codes: G06N 5/046 Forward inferencing; Production systems
• CPC Class Codes: Y10S 706/921 Layout, e.g. circuit, construction

Abstract

A production system for an expert system comprising: a production rule memory unit storing circuit conversion rules, each having a condition part describing circuit connection and an execution part describing a conversion of the condition part to an equivalent logic circuit dependent upon a predetermined semiconductor technology and further having a provisionally predetermined priority; a task data memory unit storing circuit connection data, each being subjected to an application of the circuit conversion rules; a production rule interpretation and execution unit for selecting a circuit conversion rule in accordance with the provisionally predetermined priority, collating the condition part of the selected circuit conversion rule with the circuit connection data to determine whether the condition part matches with a part of the circuit connection data and, when the both match each other, converting the part of the circuit connection data by the corresponding execution part of the circuit conversion rule to an equivalent logic circuit; further each production rule being provided with a rule flag indicating the collation failure to the circuit connection data, a rule flag memory unit for setting the rule, flag of the circuit conversion rule of which condition part did not match with any of the circuit connection data during the collation cycle, so as to inhibit collation thereafter until collation of all other circuit conversion rules is once completed, thereby increasing the operation speed of the production system for an expert system.

Claims

1. A production system for an expert system comprising;

a production rule memory unit for storing a plurality of production rules, each having a condition part and an execution part and a provisionally predetermined priority;

a task data memory unit for storing a plurality of task data, each being subjected to an application of the production rules;

a production rule interpretation and execution unit for selecting a production rule in accordance with the provisionally predetermined priority, collating the condition part of the selected production rule with the task data to determine whether the condition part matches with at least a part of the task data and, when both match each other, renewing the part of the task data by the corresponding execution part of the production rule, wherein one collation cycle of said production rule interpretation and execution unit finishes when a collation success is effected and a next collation cycle thereof starts thereafter;

each production rule being further provided with a rule flag indicating a collation failure to the task data; and

a rule flag memory unit for setting the rule flag of a production rule when a condition part thereof did not match any of the task data during the collation cycle to inhibit further collation thereafter until collation of all the other production rules is once completed.

2. A production system for an expert system according to claim 1 further comprising:

a collation success and failure cycle memory unit for storing the results of the collation in terms of collation cycle number and production rule number; and

first means for changing the priority, for the next operation, of production rules having condition parts matched with at least parts of the task data, in the order of the collation matching in accordance with the stored results in said collation success and failure cycle memory unit.

3. A production system for an expert system according to claim 2 further comprising:

second means for raising the priority, for the next operation, of production rules having condition parts matched with at least parts of the task data and for lowering the priority, for the next operation, of production rules having condition parts that do not match any of the task data, in accordance with the stored results in said collation success and failure cycle memory unit.

4. A production system for an expert system according to claim 2 further comprising:

third means for indicating a renewed priority of the production rules in response to changing by said first means.

5. A production system for an expert system according to claim 3 further comprising:

third means for indicating a renewed priority of the production rules in response to raising and lowering by said second means.

6. A production system for an expert system comprising:

a production rule memory unit for storing a plurality of production rules, each having a condition part and an execution part and a provisionally predetermined priority;

a task data memory unit for storing a plurality of task data, each being subjected to an application of the production rules;

a production rule interpretation and execution unit for selecting a production rule in accordance with the provisionally predetermined priority, collating the condition part of the selected production rule with the task data to determined whether the condition part matches with at least a part of the task data and, when both match each other, renewing at least the part of the task data by the corresponding execution part of the production rule, wherein one collation cycle of said production rule interpretation and execution unit finishes when a collation success is effected and a next collation cycle thereof starts thereafter;

a collation success and failure cycle memory unit for storing the results of the collation in terms of collation cycle number and production rule number; and

first means for changing the priority, for the next operation, of production rules having condition parts matched with at least parts of the task data, in the order of the collation matching in accordance with the stored results in said collation success and failure cycle memory unit.

7. A production system for an expert system according to claim 6 wherein said first means moves a production rule which effected collation failure at a first collation round and moves a production rule which effected collation success at a second collation round to a point immediately after a production rule which last effected collation success at the first collation round.

8. A production system for an expert system according to claim 6 further comprising:

second means for raising the priority, for the next operation, of production rules having condition parts matched with at least a part of the task data, and for lowering the priority, for the next operation, of production rules having condition parts that do not match with any of the task data in accordance with the stored results in said collation success and failure cycle memory unit.

9. A production system for an expert system comprising:

a production rule memory unit for storing a group of circuit conversion rules, each having a condition part describing circuit connection and an execution part describing a conversion of the condition part to an equivalent logic circuit dependent upon a predetermined semiconductor technology and further having a provisionally predetermined priority;

a task data memory unit for storing a group of circuit connection data, each being subjected to an application of the circuit conversion rules;

a production rule interpretation and execution unit for selecting a circuit conversion rule in accordance with the provisionally predetermined priority, collating the condition part of the selected circuit conversion rule with the circuit connection data to determine whether the condition part matches with at least a part of the circuit connection data and, when both match each other, converting the part of the circuit connection data by the corresponding execution part of the circuit conversion rule, wherein one collation cycle finishes when a collation success is effected and a next collation cycle starts thereafter;

each circuit conversion rule further being provided with a rule flag indicating the collation failure to the circuit connection data,

a rule flag memory unit for setting the rule flag of the circuit conversion rule, having condition part that did not match with any of the circuit connection data during the collation cycle, to inhibit collation thereafter until collation of all other circuit conversion rules is once completed;

a collation success and failure cycle memory unit for storing the results of the collation in terms of collation cycle number and circuit conversion rule number; and

a first means for changing the provisionally predetermined priority, for the next operation, of the circuit conversion rule having condition part matched with at least parts of the circuit connection data, in the order of collation matching in accordance with the stored results in said collation success and failure cycle memory unit.