Time in a simple model of a physical system

We build a model of time starting from the primitive concept of base-setB≡{α _i |i∈I} of all physical systems, whose elements are called pre-particles α _i . We assume thatB is a denumerably infinite set. Particles or bodies are represented by the subsets of the power setP (B) of the base-setB. A physical system is represented by a set of particles. We introduce the distinction between evolving and non-evolving particles, and assume that the former are represented by those subsets ofP (B) which are chains. Making use of the above concepts we define the state of a particle and the indicator of the state of a particle with respect to a given state of the same or another particle. Then we define in terms of indicators the concepts of instant, time-set, degenerate time-set, event, and clock. For the time related to a given clock one has a set in which the order relation is is in general not connected. Some theorems are proved.