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We present a general framework for the formal speciication and algorithmic analysis of hybrid systems. A hybrid system consists of a discrete program with an analog environment. We model hybrid systems as nite automata equipped with variables that evolve continuously with time according to dynamical laws. For veriication purposes, we restrict ourselves to(More)
— Giotto provides an abstract programmer's model for the implementation of embedded control systems with hard real-time constraints. A typical control application consists of periodic software tasks together with a mode switching logic for enabling and disabling tasks. Giotto specifies time-triggered sensor readings, task invocations, actuator updates, and(More)
We describe nite-state programs over real-numbered time in a guarded-command language with real-valued clocks or, equivalently, as nite automata with real-valued clocks. Model checking answers the question which states of a real-time program satisfy a branching-time speciication (given in an extension of CTL with clock variables). We d e v elop an algorithm(More)
A hybrid system is a dynamical system whose behavior exhibits both discrete and continuous change. A hybrid automaton is a mathematical model for hybrid systems, which combines, in a single formalism, automaton transitions for capturing discrete change with diierential equations for capturing continuous change. HyTech is a symbolic model checker for linear(More)
Hybrid automata model systems with both digital and analog components, such az embedded control programs. Many verification tasks for such programs can be expressed as reachability problems for hybrid au-tomata. By improving on previous decidability and un-decidability results, we identify the precise boundary between decidability and undecidability of the(More)
We present algorithms for computing similarity relations of labeled graphs. Similarity relations have applications for the refinement and verification of reac-tive systems. For finite graphs, we present an O(mn) algorithm for computing the similarity relation of a graph with n vertices and m edges (assuming m 2 n). For effectively presented infinite graphs,(More)