The requirements analysis of critical software components often involves a search for hazardous states and failure modes This paper describes the integration of a forward search for consequences of reaching these forbidden modes with a backward search for contributing causes Results are reported from two projects in which the integrated search method was used to analyze the requirements of crit...

It is known that bounds on the minimax values of nodes in a game tree can be used to reduce the computational complexity of minimax search for two-player games. We describe a very simple method to estimate bounds on the minimax values of interior nodes of a game tree, and use the bounds to improve minimax search. The new algorithm, called forward estimation, does not require additional domain k...

Modal logic allows us to distinguish between possibility of truth and necessity of truth. It has many uses in computer science in fields such as network security. In this talk, I will discuss some of the issues involved in automating a proof search, focusing on those that occur in forward search. In forward search, we wish to start from our assumptions and apply logical rules in order to reach ...

Recent scaling up of POMDP solvers towards realistic applications is largely due to point-based methods which quickly converge to an approximate solution for medium-sized problems. Of this family HSVI, which uses trial-based asynchronous value iteration, can handle the largest domains. In this paper we suggest a new algorithm, FSVI, that uses the underlying MDP to traverse the belief space towa...