The Truth Maintenance System (TMS) is a problem solver subsystem to make assumptions and subsequently revise their beliefs when contradiction among these assumptions is discovered by recording and maintaining the reasons for beliefs. The major functions of the TMS are to maintain justifications, to update its beliefs when premises are added or removed, and to perform dependency-directed backtracking. The TMS is an unseparable component in expert systems which need high quality decision making.
As a thesis research, the logic-based TMS combined with Hughes Aircraft Production System 2(HAPS2) as an existing rule-based system is implemented on a Kyoto Common Lisp (KCL) environment running on the SUN 3/260 workstation. Variable binding and explanation functions are also provided in the TMS applied. The TMS is evaluated using an accident identification function developed for Emergency Operating Procedures in the nuclear power plant.
