Jess, the Rule Engine for the Java Platform

Tests follow the variable name and are separated from it and from each other by an and (&) or or (|) symbol. (The variable name itself is actually optional.) Tests can be: A literal value (in which case the variable matches only that value); for example, the value 1.0 in (coordinate (x 1.0)). A variable which was assigned earlier on the rule's LHS. ................
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