6. The method of claim 1 , wherein each light path expression in the one or more light path expressions is generated by concatenating a set of event descriptors in a string.
6. The method of claim 1 , wherein each light path expression in the one or more light path expressions is generated by concatenating a set of event descriptors in a string. 7. The method of claim 6 , wherein the string may include at least one of a wildcard symbol and an operator defined in a grammar for the light path expressions.