Daniel Schwencke

Learn More
Covarieties of coalgebras are those classes of coalgebras for an endofunctor H on the category of sets that are closed under coproducts, subcoalgebras and quotients. Equivalently, covarieties are classes of H-coalgebras that can be presented by coequations. Adámek introduced a logic of coequations and proved soundness and completeness for all polynomial(More)
GSOS RULES AND A MODULAR TREATMENT OF RECURSIVE DEFINITIONS STEFAN MILIUS , LAWRENCE S. MOSS , AND DANIEL SCHWENCKE c a Lehrstuhl für Theoretische Informatik, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany e-mail address: mail@stefan-milius.eu b Department of Mathematics, Indiana University, Bloomington, IN, USA e-mail address:(More)
Completely iterative algebras (cias) are those algebras in which recursive equations have unique solutions. In this paper we study complete iterativity for algebras with computational effects (described by a monad). First, we prove that for every analytic endofunctor on Set there exists a canonical distributive law over any commutative monad M , hence a(More)
Final coalgebras for a functor serve as semantic domains for state based systems of various types. For example, formal languages, streams, nonwell-founded sets and behaviors of CCS processes form final coalgebras. We present a uniform account of the semantics of recursive definitions in final coalgebras by combining two ideas: (1) final coalgebras are also(More)
Coequations, which are subsets of a cofree coalgebra, can be viewed as properties of systems. In case of a polynomial functor, a logic of coequations was formulated by J. Adámek. However, the logic is more complicated for other functors than polynomial ones, and simple deduction rules can no longer be formulated. A simpler coequational logic for finitely(More)
Deterministic recursive program schemes (RPS’s) have a clear category theoretic semantics presented by Ghani et al. and by Milius and Moss. Here we extend it to nondeterministic RPS’s. We provide a category theoretic notion of guardedness and of solutions. Our main result is a description of the canonical greatest solution for every guarded nondeterministic(More)
GSOS RULES AND A COMPOSITIONAL TREATMENT OF RECURSIVE DEFINITIONS STEFAN MILIUS, LAWRENCE S. MOSS, AND DANIEL SCHWENCKE Institut für Theoretische Informatik, Technische Universität Braunschweig, Germany e-mail address: mail@stefan-milius.eu Department of Mathematics, Indiana University, Bloomington, IN, USA e-mail address: lsm@cs.indiana.edu Institut für(More)
  • 1