coreachable adjective1 •Mutually reachable, that is, for any two nodes n1 and n2, they are coreachable iff n1 is reachable from n2 and n2 is reachable from n1.Further, non coreachable nodes are qualified as forbidden. The loop terminates when all forbidden markings (those initially declared and those newly identified) are processed. — 2013
