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2.4.4 Forward Chaining History

Figure 2.7 KnowledgeWorks Forward Chaining History

This is obtained by choosing KnowledgeWorks > FC History . If you have just run the tutorial a window will appear of which the left column contains the entry DEFAULT-CONTEXT . These are all the contexts (rule groups) the forward chaining engine has executed (in this case only one). On the right is a detailed breakdown of what happened in each cycle within this context. You will see the rule names listed down the left, and the cycle numbers along the top. The boxes indicate which rules fired. In the last cycle, you will see a black box indicating that the rule GAME-FINISHED fired, and a outlined box for the rule PLAY . This means that the rule PLAY could have fired, but that GAME-FINISHED was preferred.

Note: you can remove the package prefixes from displayed symbols by setting the current package of the FC History tool to KW-USER , in the same way as you did for the Objects Browser tool (see Objects Browser).

Look at the definition for GAME-FINISHED (find the source using the Rule Browser) and notice that it contains :priority 15 . This means that the GAME-FINISHED rule has higher priority than the PLAY rule (which has the default value of 10 ), and so was preferred. Other methods of conflict resolution are also available.

KnowledgeWorks and Prolog User Guide (Windows version) - 6 Dec 2011