General Formal Ontology (GFO)
The category of occurrents centers around the
more intuitive notion of processes. It captures
processes themselves and several other categories that can be derived
from processes and share the feature of being extended in time (in
various ways). Accordingly, processes have special connections
to time entities, i.e., to chronoids and their boundaries.
Some examples of occurrents include: a rhinitis, seen as a sequence of different
states of inflammation; writing a letter; sitting in front of a computer viewed
as a state extended in time; a clinical trial;
the treatment of a patient; the development of a cancer; a lecture in the sense of an actual event as well
as a series of actual events, but opposed to the abstract notion of
lecture; an examination.