A constructivist approach to tense and aspect: From text to polytyped strings

The authors describe a system for extracting temporal and aspectual information from texts in French. A representation is constructed using a local formalism called the polytyped strings language. For each proposition, the first module processes the semantic value (e.g., state, habit, activity in progress) with the help of rules exploring all lexical categories (e.g. temporal connectives, adverbs). A second module creates the representation of temporal and aspectual knowledge of the text by constructing a temporal constraint network whose vertices are finite increasing sequences of boundaries called polytyped strings (PTS) and edges are labelled by relations between PTS