| Number | Date | Country | Kind |
|---|---|---|---|
| 6-201210 | Aug 1994 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5333236 | Bahl et al. | Jul 1994 | |
| 5333266 | Boaz et al. | Jul 1994 | |
| 5568383 | Johnson et al. | Oct 1996 |
| Entry |
|---|
| P.H. Winston, "Control Metaphors", Artificial Intelligence, 2nd Ed., Addison-Wesley Publishing Company, Inc., pp. 136-161, 1984. |