helle hvid hansen

 

Selected talks

  • Bisimulation for Weakly Expressive Coalgebraic Modal Logics [ slides ]
    Contributed talk at Algebra and Coalgebra in Computer Science (CALCO 2017), Ljubljana, Slovenia.
  • Game Logic: Coalgebraic Completeness and Automata [ slides ]
    Invited talk at Algebra and Coalgebra Meet Proof Theory VII (ALCOP 2017), University of Strathclyde, Glasgow, UK.
  • Coalgebraic dynamic logic [ slides ]
    Invited talk at Dynamics in Logic IV, 29 Oct 2016.
  • Coalgebraic dynamic logic: basic completeness results [ slides ]
    Invited talk at COIN: Coalgebra in the Netherlands, 9 Nov 2015. (Presentation for a coalgebra audience)
  • Coalgebraic dynamic logic: basic completeness results [ slides ]
    Invited talk at the Oxford Advanced Seminar on Informatic Structures (OASIS), 6 Nov 2015.
  • Coinductive specification of k-regular sequences [ slides ]
    Invited talk at the Scottish Theorem Proving Seminar, Dundee, 7 Oct 2015.
  • Brzozowski Minimization via Dual Adjunctions [ slides ]
    Invited talk at the Eleventh International Tbilisi Symposium on Language, Logic and Computation (TbiLLC 2015), Tbilisi, Georgia, 21–26 September 2015.
  • Coalgebraic PDL [blackboard talk]
    Workshop on Coalgebras in Quantum Physics, 15 - 19 March 2015, Bellairs Research Institute, Barbados.
  • Strong Completeness for Iteration-Free Coalgebraic Dynamic Logics [ slides ]
    Algebra-Coalgebra seminar, ILLC, University of Amsterdam, 16 Feb 2015.
  • A Coalgebraic View on PDL and Game Logic [ slides ]
    Brouwer seminar, Radboud University Nijmegen, 10 Oct 2014.
  • Strong Completeness for Iteration-Free Coalgebraic Dynamic Logics
    Theoretical Computer Science (IFIP-TCS), 1 - 3 Sep 2014, Rome.
  • The Final Deterministic Automaton of Streams [ slides ]
    Brouwer seminar, Radboud University Nijmegen, 29 April 2014.
  • Streams and Coalgebra, a tutorial [ Lecture 1 | Lecture 2 ]
    Representing Streams II, Lorentz Center, Leiden, Jan 2014.
  • Distributive Laws for Monads with Equations [ slides ]
    Coalgebra in the Netherlands (COIN), Nijmegen, June 2013.
  • Presenting Distributive Laws
    Bellairs Workshop on Coalgebra, Barbados, March 2013.
  • Brzozowski revisited: minimal language acceptors via dual adjunctions [ slides ]
    (includes Brzozowski for weighted automata, and generalised dual adjunction)
    Brouwer seminar, Radboud University Nijmegen, 30 Oct 2012.
  • Brzozowski's algorithm (co)algebraically [ slides ]
    (with Alexandra Silva) Dagstuhl seminar on Coalgebraic Logics, 9 Oct 2012.
  • Brzozowski's algorithm: minimal language acceptors via duality [ slides ]
    (includes Brzozowski for deterministic automata, and categorical perspective)
    Coalgebra in the Netherlands (COIN), Centrum Wiskunde & Informatica, Amsterdam, 4 Oct 2012.
  • Coalgebraic Modal Logic, an Introduction
    ACG Colloquium, Centrum Wiskunde & Informatica, Amsterdam, 13 December 2011.
  • Experiences and Insights from the INESS Project .
    RSTRC (Railway Safety Technology Research Centre) Workshop, The University of York, England, 27 September 2011.
  • Pointwise extensions of GSOS-defined operations, from bitstreams to Mealy machines Theoretical Computer Science Seminar, Vrije Universiteit Amsterdam, 27 May 2011.
  • Translating Interlocking Models: From xUML to mCRL2 and Back [ slides ]
    Formal Methods for Components and Objects (FMCO 2010), Graz, Austria, 29 November 2010.
  • Verification of Executable UML Model in the Railway Signalling Domain
    Systems Engineering Seminar, Eindhoven University of Technology, 11 November 2010.
  • Specifying Pointwise Operations on Final Coalgebras
    The Categorical Flow of Information in Quantum Physics and Linguistics, University of Oxford, UK, 30 October 2010.
  • Stream Functions from a Coalgebraic Perspective [ slides ]
    Streams Seminar, Radboud University Nijmegen, 18 January 2010.
  • Bialgebras, Bitstream Arithmetic and Mealy Machines
    Dagstuhl Seminar on Coalgebraic Logics, Dagstuhl, Germany, 8 December 2009.
  • INESS: INtegrated European Signalling System
    CeDICT Day on Dependable Systems, Utrecht, The Netherlands, 24 April 2009.
  • Coalgebraising Subsequential Transducers [ slides ]
    Workshop on Coalgebraic Methods in Computer Science (CMCS 2008), Budapest, Hungary, 4 April 2008.
  • Neighbourhood Semantics: a coalgebraic perspective
    (with Clemens Kupke) Philipps University Marburg, Germany, 18 February, 2008.
  • Bisimulation for Neighbourhood Structures
    Conference on Coalgebra and Algebra in Computer Science (CALCO 2007), Bergen, Norway, 23 August 2007.
  • Bisimulation for Neighbourhood Models [ slides ]
    TCS seminar, Vrije Universiteit Amsterdam, 23+30 March, 2007.
  • Subsequential Transducers and Coalgebra [ slides ]
    Automata: from Mathematics to Applications (AutoMathA 2007), Mondello (Palermo), Italy, 18-22 June, 2007.
  • Synthesis of Mealy Machines Using Derivatives [ slides ]
    Workshop on Coalgebraic Methods in Computer Science (CMCS 2006), Vienna, Austria, 25 March 2006.
  • Bounded Morphisms and Bisimilarity: a Coalgebraic Perspective
    (with Clemens Kupke) Forth and Back for 40 Years, symposium on the occasion of the 40th anniversary of the p-morphism. Institute for Logic, Language and Computation (ILLC), University of Amsterdam, 27 June 2006.
  • Coalgebras for Sequential Transducers
    Workshop on Modal Logic, Stone Duality and Coalgebras, University of Leicester, 12-13 June 2006.
  • A Coalgebraic Perspective on Monotone Modal Logic
    Workshop on Coalgebraic Methods in Computer Science (CMCS 2004), Barcelona, Spain, 27 March 2004.
  • Axiomatising Nash-Consistent Coalition Logic
    Joint European Conference on Logics in Artificial Intelligence (JELIA 2002), Cosenza, Italy, 23-26 September 2002.