A theory of monitors

We develop a behavioural theory for monitors — software entities that passively analyse the runtime behaviour of systems so as to infer properties about them. First, we extend the monitor language and instrumentation relation of [17] to handle piCalculus process monitoring. We then identify contextual behavioural preorders that allow us to re-late monitors according to criteria defined over monitored executions of piCalculus processes. Subsequently, we develop alternative monitor pre-orders that are more tractable, and prove full-abstraction for the latter alternative preorders with respect to the contextual preorders.peer-reviewe

Automaton-based parsing for lexicalized grammars

In wide-coverage lexicalized grammars many of the elementary structures have substructures in common. This means that during parsing some of the computation associated with different structures is duplicated. This paper explores ways in which the grammar can be precompiled into finite state automata so that some of this shared structure results in shared computation at run-time. 1 Introduction This paper investigates grammar precompilation techniques aimed at improving the parsing performance of lexicalized grammars. In a wide-coverage lexicalized grammar, such as the XTAG grammar (XTAG-Group, 1995), many of the elementary structures 1 have substructures in common. If such structures are viewed as independent by a parsing algorithm, the computation associated with their shared structure may be duplicated. This paper explores ways in which the grammar can be precompiled so that some of this shared structure results in shared computation at run-time. We assume as a starting point a co..