anything that is not a relation thing that "occurs" in a (real or imagined) region of time and space situation not changing and not making a change during a given period of time situation that makes a change during some period of time process considered instantaneous from some viewpoint; classification under this category is application-dependant cognitive activity to solve a problem processes modelled in knowledge acquisition, e.g. a diagnostic a task composed of more basic tasks making a knowledge based system making a knowledge based system using KADS methodology situation known through the senses rather than by reasoning e.g. a causal situation thing that can be "involved" in a situation space region or thing occupying a space region point or extent in space spatial entity made of matter e.g. an animal, a cell entity that is alive e.g. a bottle entity that is no more alive e.g. knowledge, motivation, language, measure feature/product of mental activity, e.g. feeling content/element of a description description of a situation e.g. a narration, an hypothesis report, story, biography, etc. process history/specification information describing a past process information specifying the possible executions of some processes, e.g. a computer program, a musical score script on motions e.g. a computer program, a schedule, a musical score e.g. a network protocol such as HTTP 4.0 e.g. FTP, HTTP dataflow graph of "inferences" (tasks) the inputs/outputs of which are described by "roles" e.g. a syntax, a language, a script natural/artificial language a version of the Extensible Markup Language an XML notation for the RDF model description in http://www.w3.org/TR/1999/REC-rdf-syntax-19990222 atomic or structured two instances: true and false e.g. file, image (but not disk or paper) a part of a document the entire content of a document e.g. mass, mass unit, 1 kg, frequency, [2-3] hz, color, blue, speed, 1 m/s measure of points or intervals in time e.g. length measure in meters e.g. mass/length/color measure e.g. a speed measure in km/h e.g. "Never" might be declared as an instance something gathering separated things (entities/situations) alternatives (exclusive or inclusive?) bag of OR-ed elements bag of XOR-ed elements container where duplicate elements are not allowed set of OR-ed elements set of XOR-ed elements all classes are instance of that object all binary relation classes are instance of that object classification under this category is application-dependant divisible entity with discrete parts e.g. an agent, an owner recipient of a process something (animal or software agent) able to act goal directed causal entity (ex:a problem solver or an interactional agent) for example an animal or an AI-agent for example a person e.g. AI_Agent e.g. supernatural forces non conscious entity and not AI_Agent an entity that has been imagined e.g. a cartoon character category to classify things according to roles/viewpoints; classification under this category is application-dependant Peirce/Sowa's notion of "thirdness" e.g. something needed for an application superclass of relations; instance of rdf#Property number of elements an average on the values instance of _total_order_relation e.g. [a car, color: red] e.g. rdf#type, rdfs#sub_class_of, pm#part, pm#equal instance of _partial_order_relation_class general class to specialize member relation in WordNet instance of equivalence_relation_class "=" in KIF