Time and Defeasibility in FIPA ACL Semantics

Inferences about speech acts are often conditional, nonmonotonic, and involve the issue of time. Most agent communication languages, however, ignore these issues, due to the difficulty to combine them in a single formalism. This paper addresses such issues in defeasible logic, and shows how to express a semantics for ACLs in order to make nonmonotonic inferences on the basis of speech acts.