Representing and Reasoning about Motion in a Two-Dimensional World

This paper presents a point based spatio-temporal rst order logic for representing the qualitative and quantitative spatial temporal knowledge needed to reason about motion in a two-dimensional space. The knowledge of a simpli ed world, a two-dimensional street network with active tra c lights, is represented, and the reasoning problem of how a robot moves from one place to another in the world is formalized with the proposed logic.