This command provides some interpretation of backtraces generated during chunking. If no option is given, then a list of all chunks and justifications is printed.
The two most useful variants are explain-backtraces prodname and explain-backtraces name n. The first variant lists all of the conditions for the named chunk or justification, and the ground which resulted in inclusion in the chunk/justification. A ground is a working memory element (WME) which was tested in the supergoal. Just knowing which WME was tested may be enough to explain why the chunk/justification exists. If not, the conditions can be listed with an integer value. This value can be used in explain-backtraces name n to obtain a list of the productions which fired to obtain this condition in the chunk/justification (and the crucial WMEs tested along the way). Why use an integer value to specify the condition? To save a big parsing job.
If an option is given, it must match one of the following forms:
save_backtraces mode must be on when a chunk or justification is created or no explanation will be available. Explain-backtraces mode is toggled using the save_backtraces boolean variable. save_backtraces is off by default. When explain mode is on, more memory is used, and building chunks and justifications will be slower.