Four dialogue systems

The paper describes four dialogue systems, developed in the tradition of Charles Hamblin. The first system provides an answer for Achilles in Lewis Carroll's parable, the second an analysis of the fallacy of begging the question, the third a non-psychologistic account of conversational implicature, and the fourth an analysis of equivocation and of objections to it. Each avoids combinatorial explosions, and is intended for real-time operation.