Natsuki Urabe

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We introduce notions of simulation between semiring-weighted au-tomata as models of quantitative systems. Our simulations are instances of the categorical/coalgebraic notions previously studied by Hasuo—hence soundness wrt. language inclusion comes for free—but are concretely presented as matrices that are subject to linear inequality constraints.(More)
Notions of simulation, among other uses, provide a computationally tractable and sound (but not necessarily complete) proof method for language inclusion. They have been comprehensively studied by Lynch and Vaandrager for nondeterministic and timed systems; for (nondeterministic) Büchi automata the notion of fair simulation has been introduced by Henzinger,(More)
Despite its success in producing numerous general results on state-based dynamics, the theory of coalgebra has struggled to accommodate the Büchi acceptance condition—a basic notion in the theory of automata for infinite words or trees. In this paper we present a clean answer to the question that builds on the " maximality " characterization of infinite(More)
Despite its success in producing numerous general results on state-based dynamics, the theory of coalgebra has struggled to accommodate the Büchi acceptance condition—a basic notion in the theory of automata for infinite words or trees. In this paper we present a clean answer to the question that builds on the " maximality " characterization of infinite(More)
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