A circumscriptive calculus of events

摘要

A calculus of events is presented in which domain constraints, concurrent events, and events with nondeterministic effects can be represented. The paper offers a nonmonotonic solution to the frame problem for this formalism that combines two of the techniques developed for the situation calculus, namely causal and state-based minimisation. A theorem is presented which guarantees that temporal projection will not interfere with minimisation in this solution, even in domains with ramifications, concurrency, and nondeterminism. Finally, the paper shows how the formalism can be extended to cope with continuous change, whilst preserving the conditions for the theorem to apply.