Forward chaining RULESThe forward chaingin RULES are very similar to the first order production rules used in the backward chaining version of the expert system, XPS.
The main difference is the action or consequence part: while in the backward chaining branch, this is always an ASSIGNMENT setting the value of a DESCRIPTOR, each forward chaining RULE executes one or more from a repertoir of FUNCTIONS in its concequence part.
Basic RULE syntax and logic
RTXPS uses basid production RULES in forst order logic.
The generic RULE syntax is:
where CONDITION is short for CONDITION = TRUE, and a construct of the form:
IF TRUE (unconditionally true, will always execute) IF function() arbitrary function call, using DESCRIPTORs as arguments or uses the dynamic Knowledge Base for its context/input, that returns TRUE or FALSE IF DESCRIPTOR OPERATOR VALUE (direct comparison/evaluation see below, or triggering backward chaining inference tree of arbitrary nesting and number of RULES; alternative METHODS/branches and optional defaults guarantee completion of the inference even with limited/lacking data)
Please note that the final ELSE clause as well as AND in the consequence part of a RULE is optional.
The forward chaining RULES can be edited and managed with an interactive web-based tool, the RTXPS rule editor.
Data base structure
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