Department of Informatics, Kings College London, The Strand, WC2R 2LS, London, UK. carl.barton@kcl.ac.uk.|Inria Saclay-Île de France, AMIB, Bâtiment Alan Turing, Palaiseau, France. alice.heliou@lix.polytechnique.fr.|University of Rouen, LITIS EA 4108, TIBS, Rouen, France. laurent.mouchard@univ-rouen.fr.|Department of Informatics, Kings College London, The Strand, WC2R 2LS, London, UK. solon.pissis@kcl.ac.uk.