43 citations · 101 across the 13 of their papers we have counts for
13 papers
Algebraic Presentation of Semifree Monads
Aloïs Rosset, Helle Hvid Hansen, Jörg Endrullis
Monads and their composition via distributive laws have many applications in program semantics and functional programming. For many interesting monads, distributive laws fail to ex…
Logic-Induced Bisimulations
Jim de Groot, Helle Hvid Hansen, Alexander Kurz
We define a new logic-induced notion of bisimulation (called -bisimulation) for coalgebraic modal logics given by a logical connection, and investigate its properties. We show t…
Minimisation in Logical Form
Nick Bezhanishvili, Marcello Bonsangue, Helle Hvid Hansen +4
Stone-type dualities provide a powerful mathematical framework for studying properties of logical systems. They have recently been fruitfully explored in understanding minimisation…
Arrow's Theorem Through a Fixpoint Argument
Frank M. V. Feys, Helle Hvid Hansen
We present a proof of Arrow's theorem from social choice theory that uses a fixpoint argument. Specifically, we use Banach's result on the existence of a fixpoint of a contractive…
Completeness for Game Logic
Sebastian Enqvist, Helle Hvid Hansen, Clemens Kupke +2
Game logic was introduced by Rohit Parikh in the 1980s as a generalisation of propositional dynamic logic (PDL) for reasoning about outcomes that players can force in determined 2-…
Parity Games and Automata for Game Logic (Extended Version)
Helle Hvid Hansen, Clemens Kupke, Johannes Marti +1
Parikh's game logic is a PDL-like fixpoint logic interpreted on monotone neighbourhood frames that represent the strategic power of players in determined two-player games. Game log…