A ruleset is a sequential array of rules (including ground atoms, view definitions, transition rules). See example below.
[q(b), r(X) :- p(X,Y) & q(Y), a(X,Y) ==> p(X,Y)]
EpilogJS rulesets can be either indexed or unindexed. An indexed ruleset is one that is also an index. (See index.) In EpilogJS, rulesets are "rule" indexed by default (see ruleindex). The user can alter this default by changing the value of the variables ruleindexing. An unindexed ruleset is one that does not have an index. As a result, lookup, update, and inference procedures must search the entire ruleset rather than relying on an index to economize on this work.