The purpose of this lesson is to expose you to some of the top level collections in Cyc and give you an idea of how they relate to each other.
This slide shows the organization of some of the most fundamental collections in Cyc. For example, the collection #$Intangible is related to #$Thing with a solid green line, meaning that #$Intangible generalizes to (or is a sub-collection of) #$Thing. #$Thing is the supreme collection. Everything in the universe (even intangible things) is an instance of #$Thing. Consequently, every collection is a specialization of of #$Thing.
#$Intangible is the collection of all things that cannot be touched. #$TemporalThing is the collection of things that exist in time. An integer would not be in this collection because integers do not exist at a specific time -- they are abstract, or timeless. Instances of #$SpatialThing-Localized are simply those things that have a location in space.
#$ExistingStuffType and #$ExistingObjectType correspond to the common-sense notions of “stuff” and “object” respectively. Water is stuff, but a lake is an object. The collection #$Water is stuff-like in that each portion of an instance of #$Water is also an instance of #$Water. #$Lake is object-like in that typically any proper part of a lake is not itself a lake.
Let’s look at a specific lower-level collection in detail. The collection #$Dog is asserted in Cyc to be an instance of the following collections: #$OrganismClassificationType, #$BiologicalTaxon, #$BiologicalSpecies, and #$DomesticatedAnimalType.
#$Dog is asserted to be a specialization of the collection #$CanineAnimal for the obvious reason that every instance of #$Dog is also an instance of #$CanineAnimal.
“Genls” is a transitive relation, so any genls of a genls of #$Dog is itself a genls of #$Dog. For example, #$CanineAnimal is a genls of #$Dog and #$Carnivore is a genls of #$CanineAnimal. Consequently, #$Carnivore is a genls of #$Dog. By the same reasoning, every genls of #$Carnivore is also a genls of #$Dog. This slide shows all collections that are genls of #$Dog.
To take a few examples, Cyc knows that the members of #$Dog are also: agents, air-breathing vertebrates, heterotrophs (they require organic nutrients in order to survive), hexalateral objects (meaning that it is appropriate to refer to a front side, a back side, a top, a bottom, a left side, and a right side -- unlike a tennis ball which has no sides), perceptual agents (they can perceive things), and spatially localized things (they have a location in physical space), etc.
In contrast to the previous list of 45 collections of which #$Dog is a spec, this is a list of the collections of which #$Dog is an instance. Earlier we listed the four collections of which #$Dog is asserted to be a member. From this, Cyc knows that #$Dog is actually an instance of eleven collections. This is because each of the first four collections collectively are specializations of seven other collections.
#$Dog is an instance of #$ExistingObjectType, meaning that any part of a dog is not a dog on its own (a dog’s leg is not a dog).
#$Dog is an instance of #$TemporalStuffType, meaning that anything that is a dog at one time will always be a dog (this is not true of a teacher, for example, who can be a teacher one year and an attorney the next year).
#$Dog is an instance of #$OrganismClassificationType which means, roughly, that this collection is used in the scientific classification of organisms.
This concludes the lesson on top level collections in Cyc.