In the first meeting of the AI Seminar Series, Chris Ewin will talk to us about reasoning in the situation calculus!
Title: Transforming Situation Calculus Action Theories for Optimised Reasoning
Speaker: Chris Ewin
When: Tuesday, 1st April 11AM
Where: Doug McDonnell-10.05
Among the most frequent reasoning tasks in the situation calculus are
projection queries that query the truth of conditions in a future state of
affairs. However, in long running action sequences solving the projection
problem is complex. The main contribution of this work is a new technique
which allows the length of the action sequences to be reduced by reordering
independent actions and removing dominated actions; maintaining semantic
equivalence with respect to the original action theory. This transformation
allows for the removal of actions that are problematic with respect to
progression, allowing for periodical update of the action theory to reflect
the current state of affairs. We provide the logical framework for the general
case and give specific methods for two important classes of action theories.
The work provides the basis for handling more expressive cases, such as the
reordering of sensing actions in order to delay progression, and forms an
important step towards facilitating ongoing planning and reasoning by long-
running agents. It provides a mechanism for minimising the need for keeping
the action history while appealing to both regression and progression.
Chris Ewin is a PhD student under the supervision of Associate Professor
Adrian Pearce. He is currently exploring methods for more efficient reasoning
in the situation calculus. His research interests include agent intelligence,
reasoning about actions and change, and the situation calculus.