http://popups.lib.uliege.be/1373-5411/index.php?id=2076 Index terms fr 0 http://popups.lib.uliege.be/1373-5411/index.php?id=2074 Transitions have been studied in physics, mathematical system theory, automata theory, Petri nets, and many other theories - and they are always introduced with reference to the states of a given system. But usually the notion of 'state' is defined in an abstract way which is not related to a general formal notion of 'time' in the actual system description. That causes many problems in applications. By contrast, in this paper the author introduces transitions in conceptual time systems mainly as pairs of time objects. Then transitions between situations, states, time states, and phases can be induced easily. That leads to very effective temporal representations of processes, as demonstrated by, for example, applications in an air-conditioning plant. Mon, 29 Jul 2024 11:17:06 +0200 Mon, 29 Jul 2024 11:17:18 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=2074