Abstract

The existence of differences in time, meant to be structure ‹T,<›, where the earlier-later relation < is a linear ordering, dense and without the first and the last element, is a sine qua non condition of changes taking place at any temporal instant. Therefore it is impossible to give a definition of the operator of change ↑ (the intended meaning of the phrase „↑α” is „it is changing now what a states”) in the language Lͭ of Tense Logic calculi containing, besides classical sentential connectives, temporal categories: G, H, F, P. The paper contains the proof of this statement