General Formal Ontology (GFO)
8.1 Processes and Time, Process Boundaries, and Processual Roles
The category of processes captures those entities that develop
over time or unfold in time. Accordingly, processes are tied to
temporal entities in a special way, which we call the projection
relation (connecting a process with its
Sometimes, e.g. with a series of events considered as a whole,
the time entity appears to be a non-connected aggregate of chronoids
(i.e., a time-region). In this case, however, the process of the
lecture series can be derived from the processes of the separate
lectures. More precisely, we call these entities process
aggregates or generalized
many cases what is said about processes herein can be easily extended
to process aggregates.
Just as parts of chronoids can be chronoids themselves, we assume
that parts of processes are
always processes themselves.
Another temporally derived notion is the idea of meeting processes.
Two processes meet if their corresponding chronoids temporally meet.
If a process is projected onto a chronoid in terms of ,
each time-boundary of refers to a presential
, which is called the boundary of the process, denoted by
, which further implies . Analogously to
chronoids and time-boundaries,
The boundaries of processes are not
considered to be parts of processes, because parts of processes are
themselves processes and cannot exist at a single time-point.
Secondly, processes cannot be considered as mere
aggregates of their boundaries.
In a general sense, a presential identified as a process boundary will
be classified as a configuration, i.e., a
conglomeration of material structures, qualities and relators (see
sect. 11). Every constituent of that
configuration is said to participate in
, a relation that is expressed as .
Apart from participation based on time-boundaries, a notion of
participation of persistants is required. Consider John drinking some
water, . This corresponds to a participation relation between the
persistant and , because every presential instance of
is constrained to a single time boundary. On the other hand,
the persistant gives rise to a part or a ``layer'' of the process, not
cut along the temporal dimension, but regarding persistant participants.
Such parts of a process are called processual roles, because they
essentially capture the role of the participant in a process. In the
given example, John plays the role of the drinker, while the water has
the role of the ``drunken''. To a large extent, processual roles exhibit
the character of processes, i.e., they are temporally extended entities.
However, the processual roles of a process are mutually dependent, i.e.,
they cannot exist independently.
The notion of processual roles can be generalized as a structural
layer of a process. A structural layer of some process
is a ``portion'' of satisfying the following conditions:
- is a process, such that every boundary contains a material structure,
- and are projected onto the same chronoid, and
- Let , be arbitrary time-boundaries of the framing chronoid of
, such that occurs before , and let
. Then: if is a material structure that is contained
in the -boundary , and is a material structure that is contained
in the -boundary , and , are ontically connected, ,
then is contained in the corresponding -boundary , where