Efficiently organizing objects in a rete pattern matching network

Claim 1

An improved computer method for optimizing the ordering of tests in an expert system rule from which a RETE network is to be derived comprising the following steps: building separate lists of positively quantified tests, negatively quantified tests and mixed quantified tests in a computer memory; for each of the lists, constructing in memory a shuffleboard data structure containing a set of nodes linked together, said nodes corresponding to variables referenced by the tests; identifying all tests containing the same variable and including a pointer to the first test referencing that variable within each of the nodes containing the duplicate variables; working from the last condition to the first condition, construct a flow list of variables by first adding each variable encountered in the shuffleboard to the flow list, removing that node from the shuffleboard, and if the node contains a pointer to other occurences of that same variable, removing those nodes from the shuffleboard and processing all the variables associated with those tests; repeating the prior step for each variable encountered while working from the last condition to the first condition until all nodes are removed; and constructing an optimized RETE network using the resultant flow list of variables.