Faculteit der Letteren
9700 AS Groningen
Reasoning in time about time requires a dynamic logic of tense and aspect, such as the representational system of Dynamic Aspect Trees with situated inferences, modelling what may be concluded from the current structure of the information. Assuming that the interpretation of ordinary English discourse updates a given information structure, adjustments in the contextual parameters must preserve information by immunizing it against future updates. A fundamental division of semantic labor is proposed between structure building dynamic information and structure preserving static information which spreads through the tree by structural rules with directed modalities constraining possible updates.