6 results
Dirk Pattinson ; Lutz Schröder.
We develop a general criterion for cut elimination in sequent calculi for propositional modal logics, which rests on absorption of cut, contraction, weakening and inversion by the purely modal part of the rule system. Our criterion applies also to a wide variety of logics outside the realm of normal […]
Published on March 17, 2011
Lutz Schröder.
We discuss the treatment of initial datatypes and final process types in the wide-spectrum language HasCASL. In particular, we present specifications that illustrate how datatypes and process types arise as bootstrapped concepts using HasCASL's type class mechanism, and we describe constructions of […]
Published on December 25, 2008
Nathan Bowler ; Sergey Goncharov ; Paul Blain Levy ; Lutz Schröder.
We study a composition operation on monads, equivalently presented as large equational theories. Specifically, we discuss the existence of tensors, which are combinations of theories that impose mutual commutation of the operations from the component theories. As such, they extend the sum of two […]
Published on September 18, 2013
Sergey Goncharov ; Lutz Schröder ; Christoph Rauch ; Maciej Piróg.
Models of iterated computation, such as (completely) iterative monads, often depend on a notion of guardedness, which guarantees unique solvability of recursive equations and requires roughly that recursive calls happen only under certain guarding operations. On the other hand, many models of […]
Published on July 4, 2019
Thorsten Wißmann ; Ulrich Dorsch ; Stefan Milius ; Lutz Schröder.
We present a generic partition refinement algorithm that quotients coalgebraic systems by behavioural equivalence, an important task in system analysis and verification. Coalgebraic generality allows us to cover not only classical relational systems but also, e.g. various forms of weighted systems […]
Published on January 31, 2020
Daniel Hausmann ; Lutz Schröder.
The coalgebraic $\mu$-calculus provides a generic semantic framework for fixpoint logics over systems whose branching type goes beyond the standard relational setup, e.g. probabilistic, weighted, or game-based. Previous work on the coalgebraic $\mu$-calculus includes an exponential-time upper bound […]
Published on July 23, 2024