Modal Predicates and Co-equations

نویسندگان

  • Alexander Kurz
  • Jirí Rosický
چکیده

We show how coalgebras can be presented by operations and equations. This is a special case of Linton’s approach to algebras over a general base category X , namely where X is taken as the dual of sets. Since the resulting equations generalise coalgebraic coequations to situations without cofree coalgebras, we call them coequations. We prove a general co-Birkhoff theorem describing covarieties of coalgebras by means of coequations. We argue that the resulting coequational logic generalises modal logic.

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عنوان ژورنال:
  • Electr. Notes Theor. Comput. Sci.

دوره 65  شماره 

صفحات  -

تاریخ انتشار 2002