Thing is the "universal collection": the collection which, by definition, contains everything there is. Every individual object, every other collection. Everything that is represented in the Knowledge Base ("KB") and everything that could be represented in the KB. Cyc is designed to support representing any imaginable concept in a form that is
immediately compatible with all other representations in the KB, and
directly usable by computer software.
Intangible Things are things that are not physical -- are not made of, or encoded in, matter. These include events, like going to work, eating dinner, or shopping online. They also include ideas, like those expressed in a book or on a website. Not the physical books themselves, but the ideas expressed in those books. It is useful for a software application to know that something is intangible, so that it can avoid commonsense errors; like, for example, asking a user the color of next Tuesday's meeting.
Individual is the collection of all things that are not sets or collections. Individuals might be concrete or abstract, and include (among other things) physical objects, events, numbers, relations, and groups. Your car is an individual, but the collection of all four-door sedans is not. This collection (unlike the car itself) is abstract: it doesn't have a location, mass, or a top speed; but it does have elements, subcollections, and supercollections. The difference between collections and individuals is somewhat like the difference between classes and instances in object-oriented programming.
Sets in Cyc, also know as Mathematical Sets, define specific groupings of things. Unlike Collections, these things don't necessarily have anything in common (except, of course, their membership in the set).
Collections in Cyc are natural kinds or classes, as opposed to mathematical sets; their instances have some common attribute(s). Each collection is like a set in so far as it may have elements, subsets, and supersets, and may not have parts or spatial or temporal properties. Sets, however, differ from collections in that a mathematical set may be an arbitrary set of things which have nothing in common. In contrast, the instances of a collection will all have in common some feature(s), some 'intensional' qualities. In addition, two collections can be co-extensional (i.e., have all the same instances) without being identical, whereas if two arbitrary sets had the same elements, they would be considered equal. Moreover, the 'best' collections to create are the ones which are impossible to define precisely, yet about which there are rules and other things to say. For example, the collection of all white cats is not a good collection to create because it's easy to define with other Cyc concepts, and there's not much to say about the collection of white cats; but the collection of white collar workers could be a good collection because it is hard to define exactly, yet there are many things to say about it.
Cyc contains assertions about logical truth that provide the core assumptions required for using Cyc to perform logical inferences. The system of logical truths is constructed via a spiraling-out process, starting with the essence of logic in CycL and extending it step by step to include useful concepts to build upon the already existing concepts in a principled way. For example, here are the beginning steps of the process:
We start with the essence of logic: True and False.
To state relationships between True and False, for example (implies True (not False)), we add the logical connectives and, or, not, and implies, and the quantifiers forAll and thereExists.
To take the objects we have introduced and group them into useful categories, we introduce isa, TruthValue, LogicalConnective, and Quantifier. We assert isas for all the things introduced in steps 1 and 2.
To state isas for the objects introduced in Step 3, we need to introduce Predicate and Collection.
To state generalizations between these collections, we introduce genls, TruthFunction, Individual, and Thing.
And so on.
Relations serve as the glue that forms concepts (like "Madonna" and "Singer") into statements (like "Madonna is a singer"). Relations are also used when connecting Cyc's knowledge to external knowledge sources, such as corporate databases and Web pages. Some relations connect statements to each other to form rules, such as "If a car was manufactured after 1995, then the car contains an air bag." Unlike other technologies that use a handful of relations, Cyc relies on an extensible set of thousands of relations. And Cyc's relations are themselves connected using relations, which provides (among other things) a kind of automatic learning. When you add the fact that an air bag is part of the safety subassembly of Car X, the KB automatically knows that Car X contains an air bag, that it contains all the parts that make up the air bag, that the air bag is inside Car X, etc. This happens as a result of the already established relationships connecting contains, parts and inside.
Paths are either a non-self-crossing path or a cycle. A path may be spatio-temporally abstract (e.g. links in Graph Theory), spatially-located but intangible (e.g. a latitude line might be used as a path in some system), or fully concrete (such as a road, railroad, sea-lane, cowpath, pipe, blood vessel, fiber, or wire). A path can be anything that is used as a path in some path system. For example, an orange is not a customary path, but it can be a path for ants in a specified ant path system. For any path, there can be a traversal of something moving along the entirety of that path (and a single traversal can cross itself, double back along itself, or go back and forth along some part of a path any number of times). Note that a path does not have to be an individual, because there is nothing in principle to prevent a mathematical set or a collection from being "used as a path" in some path system. For similar reasons, few if any collections or sets can definitively be considered disjoint with Paths.
Mathematical (or computational) things are intrinsically intangible and abstract. Mathematical things are abstract in the very strong sense of being nonspatial, atemporal, and massless. Examples include numbers, sets, collections, relations, algorithms, and abstract character strings.
Temporal Things have temporal extent or location, i.e. things about which one might sensibly ask "When?". Temporal Things thus are many kinds of things, including events, physical objects, agreements, and abstract pieces of time. Abstract things that are timeless -- such as mathematical sets, attributes, and numbers -- are of course not Temporal Things."
Cyc uses around 37,000 different event types to describe what happens in the world. This large number includes events that are both extremely general and extremely specific. Common event types include Buying, Singing, Thinking, Giving Something and Physical State Change Event. An example of an individual event that could be represented is, "ACME's 2002 Shareholder Meeting." Software applications that use Cyc can represent events in the KB to simulate processes, predict or plan likely participants, analyze competing scenarios and identify needed resources for events, among many other uses.
A script in Cyc is a CycL specification of a type of complex event with temporally-ordered sub-events. Applications can use scripts for script recognition -- that is, recognizing when some stated events are part of a larger, unstated, complex event which follows a script. Scripts can also be used for planning and for reading comprehension.
Artifacts are inanimate. Each artifact is an at least partially tangible thing which was intentionally created by an agent (or a group of agents working together) to serve some purpose or perform some function. In order to create an artifact, it is not necessary that an agent create the matter out of which the artifact is composed; rather, an agent can create an instance of artifact by assembling or modifying existing matter. Examples of artifacts include a wooden flute that's been whittled from a tree branch, a sawhorse that's been put together out of boards and nails, and a coin that's been minted by embossing or by melting liquid silver into a mold. In addition to the obvious human artifacts (buildings, tools, textiles, power lines), artifacts can also be certain sorts of things made by animals, such as bird nests, termite mounds, and beaver dams.
Movement is an event in which at least one object either translates some distance or moves from one rotational orientation to another, relative to a frame of reference that is not part of the translating/rotating object. The movement in question might be periodic or not, continuous or not. Examples include an airplane trip, cooking food, and a flow of electrical current.
Borders are lines, linear regions, or dividing planes or surfaces -- physical or abstract -- that constitute the boundary between (forms a border between) two regions (i.e., two Spatial Things).
Spatial Paths have spatial extent and are therefore spatially located. Examples of Spatial Paths include roads, corridors, wires, blood vessels, and nerves; however, purely abstract paths, such as those in kinship diagrams and mathematics, are not Spatial Paths. Spatial Paths may be pre-existing paths or they may be paths in some specially specified system consisting of Spatial Paths.
Spatial Things have a spatial extent or location relative to some other Spatial Thing or in some embedding space. Note that to say that an entity is a member of this collection is to remain agnostic about two issues. First, a Spatial Thing may be partially tangible (e.g. Texas-State) or wholly intangible (e.g. the Arctic Circle or a line mentioned in a geometric theorem). Second, although we do insist on location relative to another spatial thing or in some embedding space, a Spatial Thing might or might not be located in the actual physical universe. It is far from clear that all Spatial Things are so located: an ideal platonic circle or a trajectory through the phase space of some physical system (e.g.) might not be.
Agents are beings that have desires and intentions, and the ability to act on those desires and intentions. Agents may be individuals or they may consist of several agents operating together, such as a family or a corporation.
Actors are treated as a broad relation that holds between a given event and any existing thing that is meaningfully involved in the event. When we say that someone (or something) is an actor in an event, we're saying that someone (or something) is somehow saliently (directly or indirectly) involved in the event during the event. An object's merely being cotemporal with an event is obviously not sufficient for being an actor in it, nor is participating (however centrally) in a representation or re-enactment of the event. But note that being an "actor" is not restricted to things that play "active" (as opposed to passive or instrumental) roles in a given event. Some examples of Actor relations are: hostage, container used, project leader, product created, and primary object moving.
Actions are events that are carried out by some "doer". Actions are any event in which one or more actors effect some change in the (tangible or intangible) state of the world, typically by an expenditure of effort or energy. Note that it is not required that any tangible object be moved, changed, produced, or destroyed for an action to occur; the effects of an action might be intangible (such as a change in a bank balance or the intimidation of a subordinate). Note also that the doer of an action, though typically an agent, need not be (e.g. a falling rock that dents a car's roof). Depending upon the context, doers of actions might be animate or inanimate, conscious or nonconscious.
A plan is a sequence of steps which, when performed in a given temporal order, serve to carry out certain tasks or to accomplish a certain goal.
Goals. Typically, Cyc thinks of goals as characterizing relationships holding between Cyc formulas and a particular agent when the formula describes a state of affairs that the agent intends to take steps to actualize, i.e., when actualizing the state of affairs is a goal of the agent. However, it might also be seen as an attribute of the relationship between the agent and the static situation depicted by that Cyc formula.
Physical Agents both exist and are at least partially tangible. Each agent is a being that has desires and intentions, and the ability to act on those desires and intentions. Agents may be individuals or they may consist of several agents operating together.
Physical State Changes, Metamorphosis Events, and other more radical state changes are viewed as physical transformation events in which something goes out of existence and something new comes into existence.
Materials, or constituents, are used to indicate a particular partially tangible thing which makes up another (possibly non-distinct) partially tangible thing. We think of materials as a relationship between an individual object which is partially constituted by a thing, and that thing which is more or less uniformly distributed in the object. For example, the two teaspoons of chocolate syrup that I put in my milk become materials, or constituents, of my glass of chocolate milk. Note that the materials relationship does not entail any special kind of association or bond among the constituents of a thing; they might be simply mixed, they might be chemically bonded, and they might be part of some complex structure.
Parts are treated as relationships between individuals and their (individual) "parts", where this is understood in a very broad sense that includes spatial parts, temporal parts, "conceptual" parts, members of groups, and so forth. The part relationship is used to say that some thing is in some sense a part of a whole. Note that this some thing need not be a proper part of the whole: parts is a reflexive binary predicate. Important kinds of parts include the physical parts, sub-events, time-slices, sub-information, and group members.
Static Situations are a kind of temporal situation. Each static situation is a state of affairs between two or more things, persisting statically over some time interval. Static situations always have a temporal extent, and they usually have a tangible and spatial extent. As an example, consider the situation of Bill Clinton sitting in his easy chair on the evening of 7/4/96. There are participant objects such as Bill and the chair, there are relationships such as the seat of the chair supporting his bottom and his weight being off his feet, etc. In any static situation, for the participants in that situation, there is some significant or focal relationship between them which does not change. In the most typical cases, there is no important change whatsoever, e.g. someone sitting would be such a static situation. But some things represented as static situations can alternatively be represented as events. For example, a situation in which geese were flying in a flock would be static (the flock-like spatial relationship between the geese would be retained) but it would also be dynamic in that the geese were moving, so either representation could be chosen depending on the context.
Physical Objects have both a tangible (i.e. material) part and a temporal extent (i.e. they exist in time). They might or might not also have an intangible part. For example, a particular copy of a book is made of matter, has temporal extent, and also has an intangible part: the information content of the text markings on its pages.
A Law is a collection of Governmental codes of conduct that expresses a legal requirement or restriction. For instance, one law might say, effectively, that bigamy is illegal. Note that one law can be part of more than one legal code. Also note that the legal code will have many sources, which are the laws of which it consists.
Organizational Plans are plans that a particular organization has for the future. An organization uses plans to coordinate the actions of its multiple members. Plans can be represented using scripts (see Events & Scripts higher up in the pyramid).
Organizational Actions. Individuals or groups of individuals in an organization, such as a company, perform certain sanctioned actions on behalf of the entire organization. Examples include developing a product, merging with another company, offering a product for sale and advertising in a newspaper. It is useful to think of the organization as performing these actions. This is possible in Cyc, since Organization is defined to be a kind of intelligent, multi-individual agent.
An organization is a group whose group-members are intelligent agents. In each organization, certain relationships and obligations exist between the members of the organization, or between the organization and its members. Organizations include both informal and legally constituted organizations. Each organization can undertake projects, enter into agreements, own property, and do other tasks characteristic of agents; consequently, an organization is a kind of agent. Notable organizations include legal government organization, commercial organization, and geopolitical entity.
Cyc knows about many types of organizations. Facets provide one way of organizing these collections. Here are some of the facets, along with example types for each:
funding status - publicly funded, privately funded
customers - organizations with business customers, individual customers, or no customers
structural characteristic - department, branch, chain, independent organization
GeographicReach - local, national and international organizations
ProfitMotive - commercial, non-profit
Political Geography in Cyc includes definitions, rules, and assertions about geopolitical entities. It includes general information about political geography (e.g. What is a border?) as well as specific information about towns, cities, countries and international organizations.
Nations are considered to be a kind of geopolitical entity (see below). Each nation, or country, is a nation-state having its own territory, population, and government, whether or not it is fully independent. For example, Scotland is a country, even though it is a part of the United Kingdom. One kind of Nation is the "independent country". Independent countries are distinct, independent geopolitical entities generally recognized by the international community. An independent country typically has a relatively stable government, enforced borders, its own currency, laws, and culture. Examples include the United States of America, Germany, Liberia, Mongolia, India, Taiwan (the Republic of China), and Honduras.
Government is treated as a relationship between an organization and the political entity which it has governing authority over. For example, we would say that a regional government claims to be the government of some geopolitical entity (see below), is recognized as such at least informally, and effectively functions as such (by administering the internal and external affairs of that geopolitical entity), whether or not the regional government has formal diplomatic recognition. Effectively functioning as a government includes having the power to settle disputes, collect revenue, and provide services. Note that the US government is the government of the United States of America, but not that of Ohio (the State).
A Geopolitical Entity is a group of people and/or organizations that controls some geographical region. Each geopolitical entity includes a governing body, but is more than just that governing body. Some examples of geopolitical entities are the city of Tokyo (Japan), the Bronx (the borough in New York), the state of Alaska, Rwanda, Singapore, InnerMongolia, Somerset County (England), and Taiwan (the Republic of China).
Human Activities: Cyc knows about thousands of types of human activities. Here are a few of the facets (or organizing properties) by which human activities are distinguished:
number of doers - single-doer activity, multi-doer activity (e.g. two-doer, group)
thing acted on - inanimate object, animal (e.g. human), organization
effect - human creation activity, human destruction activity
thing used - human using a device, human using an animal
Commerce, or Commercial Activities, include all types of buying, selling, offering to sell, offering to buy, marketing, paying for bought items, requesting bids, performing services for hire, advertising, etc. Kinds of commercial activities include repaying loans, renting, and recalling products. Though there is a great deal of overlap between commerical activities and business events, they are not the same. Firstly, business events do not include any purely social or recreational events (whereas a weekend swap-meet, for example, would be considered a commercial activity). Secondly, not all activities carried out in pursuit of business interests fall under the definition of commercial activity above (consider head-hunting, for example).
Sports. Cyc has a well-structured taxonomy of sports and things related to sports. Formal Competitions in sports are made up of sporting events which are made up of athletic activities.
Let's start with sporting events. Each sporting event is an entire sports competition at the end of which either a winner is declared or a draw is declared. For instance, an entire sandlot baseball game would be a sporting event, but the first inning of that game would not, since the first inning is a proper part of the game, and since neither a winner nor a draw is declared at the end of the first inning. Note that several sporting events can be organized into a formal competition; for example, the 2001 World Series was a formal competition consisting of seven sporting events. Kinds of sporting events include baseball games, tennis matches, and football (American) games.
Sporting events can be broken down into the athletic activities engaged in while performing sports. An athletic activity is a purposeful, physical human activity that is related to the playing of some sport, involves physical exertion, and tends to require strength and stamina. This concept is not limited to competitive sporting events, but also includes non-competitive sports activities and exercising (e.g. spelunking, going for a jog, or shooting a few hoops).
Recreation refers to all events which animals (especially humans) do for enjoyment.
Entertainment events in Cyc are defined to be activities performed by one or more agents primarily to amuse, entertain or otherwise divert others. Every entertainment event necessarily has among its subevents both a performance and an attendance. It is thus distinguished from recreational activities: a recreational activity need not involve any entertainers, whereas an entertainment event will always involve both an entertainer and an entertainee.
Professions and Occupations provide a very useful way of grouping people in Cyc. In fact, Cyc has a concept called "Person Type by Occupation" (i.e. profession). Each profession is a collection of workers and is defined in terms of the kind of work done. The various professions correspond to jobs of all kinds, and not just to those colloquially called "professions". Examples include professional computer programmer, food service employee, medical care professional, sales representative, brewer, and many others.
Politics refers to activities, methods, and tactics in furtherance of affecting governmental policies (or sometimes activities of other large institutions).
Warfare, therefore, is considered to be a part of politics. Waging war is a kind of military conflict event and a kind of violent action. Each war waged is a state of open, armed, often prolonged conflict carried on between nations, states, or parties. It usually only ends when one of the parties surrenders.
A business is an organization intended to make profits, i.e. to make money for agents who own it. Note that not all commercial organizations are businesses. For example, in a franchise, while the parent company is regarded as a business, the sub-organizations are commercial organizations, but not businesses. Also, businesses are typically legal agents, while commercial organizations need not be.
A commercial activity is a kind of economic action and a kind of transaction. Commercial activities include all types of buying, selling, offering to sell, offering to buy, marketing, paying for bought items, requesting bids, performing services for hire, advertising, etc. Its many types include repaying loans, renting, and recalling products. Though there is a great deal of overlap between commercial activities and business events, they are not the same. Firstly, business events do not include any purely social or recreational events (whereas a weekend swap-meet, for example, would be considered a commercial activity). Secondly, not all activities carried out in pursuit of business interests fall under the definition of commercial activity above (consider head-hunting, for example).
Military Organizations are organizations whose function (and expertise) is the use of armed force, or the threat of such use, against enemies, especially other organized, armed enemies. A military organization includes its fighting forces and their command structure, together with dedicated support services controlled by that military command. Typically, there are special conditions in the relationships between a military organization and its workers, going beyond what is expected in work agreements in civilian settings, including strict sanctions to enforce obedience. Military organizations include government military organizations such as the armies, navies, and air forces of the world's governments, and in addition private armies, rebel armies, and organized mercenary units.
Everyday Living. While Cyc's "upper onotology", or more general/conceptual knowledge, is extremely important in providing infrastructure that supports efficient reasoning for the rest of its knowledge, it is the middle-level knowledge about everyday life that makes Cyc's common sense so unique and valuable. Cyc contains a variety of knowledge about the objects and events that people encounter and experience on a daily basis.
Travel in Cyc is dealt with as an event. There are several kinds of travel events, so lets consider three salient kinds: translational motion, locomotion, and taking a trip.
Translational motion events cause a location change; thus the moving object ends up in a different place than it started from: the destination is not the same as the origin. Thus, a round-trip travel event is not a translational motion event.
In locomotion events powered by a person, the object moving is an animal. Notable kinds of locomotion events include climbing, swimming, and walking on two legs. Other kinds include types of events, such as single-person canoeing and skating, in which a person moves himself or herself using a device to which s/he supplies the motive force. Note that locomotion events involving several animals working together; e.g., tandem bicycling, a crew team rowing a boat, running a three-legged race; are a different kind of locomotion event.
Each trip is an event in which a person or a group of people prepares for a trip, boards a conveyance, travels on the conveyance, and disembarks the conveyance. For somewhat more complex events that involve repeating that procedure on a return leg, there are concepts like "round trip".
Communication as an event is one in which the transfer of information between or among agents is a focal action; communicating is the main purpose and/or goal in the event. That may be contrasted with events which involve communication but wherein the focus is different, e.g., playing cards (wherein the progressive actions -- and winning -- of the game are focal). Since communicating is a kind of purposeful action, each communicating event must be intentional on the part of the sender of information; it may or may not be intentional on the part of the recipient. Hence, a speaker on a soapbox haranguing an indifferent crowd is communicating. In contrast, Juliet soliloquizing on her balcony, unaware that Romeo is listening to her, is not communicating; this information transfer would be considered eavesdropping, not communicating. Communicating may be either a one-way or a two-way transfer of information. Every communication contains at least one transfer of information between at least two agents who participate in the event. (Note that the latter requirement excludes reading and writing from communicating, when those events are just the private accessing or generating of information.) Communicating may be specialized in various ways, such as, by the method or medium used (e.g., audio, non-verbal, face-to-face presence); by the type of information involved (e.g., making an agreement); by the purpose of the communication (e.g., teaching, negotiating); by the agents involved (e.g., intra-organization communications, stage production). Examples of communication include a symphony performance, an email message, a telephone call, a speech, a handshake, issuing a traffic ticket -- all of which normally, and focally, involve communication between two or more agents.
Transportation is made up of events in which one or more objects transport one or more other objects. Each transportation event is an event in which an object (in the role of transporter) aids in the translational movement of another object (having the role of transportees), so that both objects move together along the same complete pathway. Optionally, one of these objects, or some third object moving along with them, provides the force to make the movement happen. Examples of transportation events include automobile transportation, riding a bicycle, dogs pulling goods on a sled, a wagon with groceries rolling down a hill, a person carrying clothes in a suitcase, etc. In that last case, note that the transporter is the suitcase, not the person. Note that the transporter in a transportation event need not be in motion relative to its destination throughout the transportation event; an automobile transportation is a single transportation event even if it has sub-events in which the driver and all of the passengers disembark while the car is parked and refueled. A single transportation event may also have more than one transporter. For example, a sofa may be transported accross a living room floor by two people working together. Events which are not transportation events include a river conveying some flotsam, the wind blowing a leaf, a conveyor belt moving a widget to the next person on an assembly line, or a walking beast of burden that is carrying nothing. The first three of these negative examples are stationary conveying events, since the would-be transporter doesn't actually change its overall location; in the fourth case the unburdened beast has no transportees and the event is simply the process of an animal walking.
Logistics is a field of study concerned with the flow of material and information between suppliers and consumers, usually for the purpose of creating some product or carrying out some task. Important applications include military logistics and transportation logistics.
Plants are all members of the Biological Kingdom and comprise one of the primary subjects of Biology. Plants are typically stationary, living, whole organisms; the cells of plants generally lack cholesterol and have cell walls that include substances of cellulose. Most, though not all, plants are capable of making sugars by photosynthesis processes and have green parts. Some examples of plants are rose bush, spruce tree, and moss.
Animals are typically motile, living, whole organisms; they are heterotrophs, and thus are incapable of performing photosynthesis. Animal cells contain cholesterol and lack cell walls made of cellulose. A person is considered to be a kind of animal. The collection NonHumanAnimal denotes all animals other than humans. Cyc's lexicon accounts for the fact that people often mean NonHumanAnimal when they use the word "animal".
Ecology is the study of the interrelationships between organisms and their physical environment. Cyc also knows a little about the field of Environmental Studies, which we treat as a fairly broad collection of scientific and quasi-scientific disciplines having in common a concern about the state of the environment. Environmental Studies would include Ecology, Ecotoxicology, Sustainable Agriculture, the study of energy consumption and conservation, and the study of climate change.
Living Things are structures that are composed of one or more living cells. They might either be whole organisms (like dogs or pine trees) or components of such whole living organisms (like noses, tails, and pine needles). The healthy leg of a living person is a living thing (as is the person), but an amputated leg is not. Almost every living thing is either capable of biological reproduction itself or has components which are capable of biological reproduction (such as the cells in a living arm). Red blood cells are abnormal living things in that they cannot reproduce.
Weather is treated as both a kind of event and a kind of relationship.
When treated as a physical event, each weather event is considered to be a meteorological event of some duration, occurring over some spatial region. Some weather events are almost instantaneous (for example, lightning events), while others are quite lengthy (for example, annual climate cycles). Spatially, weather events may cover a small locality or a large portion of a continent.
The relational sense of weather is used to describe the weather at a particular outdoor location. For example, to say that it's snowy in Lake Tahoe, we would use weather to relate the concept of Lake Tahoe to the concept of Snowy. Note that multiple sorts of conditions can characterize the weather at a given region at a given time; thus the truth of the weather relationship between LakeTahoe and snowy does not rule out the possibility of using weather to relate the concept of Lake Tahoe to the concept of cloudy.
Natural Geography can be thought of as consisting of all the entities which are localizable within the context of a geography, in the sense that they might plausibly be represented on a map. This includes both partially tangible entities like geographical regions, and also entities that may be wholly intangible, like territorial borders and boundaries, latitude lines and longitude lines, trajectories of missiles and courses of ships, and the Equator.
Chemistry Cyc has some competence in several different specializations of Chemistry, including the following:
Analytical Chemistry, the science of making quantitative measurements of properties of chemical compounds. It employs techniques like mass spectrometry, electromagnetic radiation spectroscopy, titration, and gravimetric analysis.
Bioanalytical Chemistry, analytical chemistry restricted to chemical substances found in living things.
Computational Chemistry, the application of computer modelling techniques to problems in chemistry.
Electrochemistry, the study of the movement and separation of charge in matter. As such, it is the study of the transfer of electrons. It has a number of applications in Analytical Chemistry.
Environmental Chemistry, essentially the application of chemistry to the diagnosis of and solution to environmental problems. It deals with such things as the analysis of toxins in samples and the explanation of ozone holes and global warming.
Perceptual Agents are all sentient agents. Perceptual agents are individual agents capable of performing acts of perceiving. In many cases, information that a perceptual agent gathers through perceiving can influence certain other of the agent's actions.
Sentient Animals are animals which have a mind and are capable of conscious thought, or at least are best treated as such if you have to deal with them.
Emotion, or mental feelings, can be experienced in various degrees of intensity. An attribute of feeling is some particular "relative amount" of happiness, confidence, fear, or whatever. These "relative amounts" can be measured and described with terms such as "low amount of", "very high amount of", etc. For example, Cyc can deal with the attribute of feeling a relatively low amount of happiness. (Note that Happiness itself is not an individual feeling attribute but type of feeling -- instances of which are the individual attributes of feeling particular relative amounts of happiness; a low amount of happiness is one such instance. Feeling types organize into a lattice; for example, there are several more specialized forms of happiness that are present in Cyc's ontology, such as Elation, Delight, Triumph-TheFeeling, etc.
Perception in Cyc is an event in which an agent (a perceptual agent) acquires information through the exercise of its senses. Examples include reading, tasting something and listening to music.
Belief. Saying that an agent believes a given proposition means that the agent subscribes to the truth of the proposition. Note that the proposition might or might not actually be true. We can also talk about "belief statements" of a particular belief system. Each belief system is an ideology (systems of belief) in terms of which an agent characterizes (i.e., makes sense of) the world. Some belief systems are: Vegetarian Beliefs, German Nazi Ideology, Republican Party Ideology, Communist Ideology, Pacifist Ideology, and Atheism.
Cyc has knowledge of the thousands of anatomical parts that make up the human body, including organs, bones, glands, skin, etc. Cyc knows how many of each there typically are, where they are situated with respect to each other, whether they are external or internal, and much more. Cyc also has some knowledge of diseases, ailments, and the parts of the body they effect.
Physical Artifacts have a tangible (i.e. material) part and a temporal extent (i.e. it exists in time). It might or might not also have an intangible part. For example, a particular copy of a book is made of matter, has temporal extent, and also has an intangible part: the information content of the text markings on its pages. Physical artifacts include things as diverse as lenses, folded objects, the back of the hand, a flame, and vapor.
Products are individual goods, services, investments, etc.-- basically anything that is offered for money or trade. An object is a Product while it is in storage to be sold at some later point, while it is for sale, and throughout any after-purchase warranty or service period. After that, the object is no longer thought of as a Product, unless it is placed on sale again. An instance of ServiceProduct is an event that is paid for or for which payment was intended/expected.
Examples of Product include a Lexus sedan in the showroom, a package of French fries being handed over the counter at a fast-food restaurant, a commercial massage, a bouquet of flowers in the window of a florist shop, a share in a money market fund, and the services of a real estate agent. The French fries being handed around the back seat of a car, the flowers being given to a sweetheart, or a free massage are not Products.
Cyc can also treat "product" as a relationship between one of the intended outputs of an event and the event itself. For unintended outputs, Cyc uses a different relationship, called "byProducts". Cyc leverages its knowledge of products with its knowledge of types of products. Cyc groups products by type -- i.e. a kind of substance, object, or action -- that is produced (or performed) and is sold as a product. Examples of product types include gift certificate, hard disk drive, plastic wrap, and service event. Non-examples include bread, since not all bread is produced to be sold (think "home-made"); but the kind of bread which is created to be a product is a product type. Product types aren't defined to be either stuff or objects because some product types can be stuff (condsider ketchup), and some product types can be objects. Note that not every conceivable kind of product constitutes a product type; only those kinds that correspond (in some broad sense) to categories under which products are produced, bought, or sold should be product types. Product types that are specific to a single brand name and product versions are even more specialized kinds of product types.
Physical Devices are artifacts with relatively rigid, set shape, designed for a specific use or to perform a specific function. Kinds of physical devices thus include (among others) road vehicles, motorboats, hand tools, and plumbing fixtures. Note that artifacts which are only to be viewed or can only be "used" in a very loose or metaphorical sense, such as a buoy, a sculpture, a flower bed, or a billboard, are not considered to be physical Devices. Moreover, artifacts which have a specific use or function, but which do not have a relatively rigid, set shape are not physical devices; for this reason, neither gasoline nor anti-freeze are kinds of physical devices."
Conceptual Works include novels, movies, musical compositions, speeches and any other abstract creations which either have associated abstract information structures (symbols arranged in a certain way, like a sentence or a diagram) or have versions that have associated abstract information structures. Conceptual works or versions of conceptual works can be instantiated in information-bearing things; every such instantiation of a conceptual work will also be an instantiation of an abstract information structure. Positive examples of conceptual works include: the novel Moby Dick (as opposed to any particular printed copy of the book), Beethoven's 9th Symphony (as opposed to any performance of this symphony or any copy of its score). Negative examples include games and awards -- these are considered "devised practice or works" but not conceptual works because they do not have associated abstract information structures.
Literature in Cyc refers to all works of literature, broadly construed. Thus it includes articles and essays, as well as novels and poems. There are three main assumptions that Cyc makes about all works of literature:
Works of literature are each conceptual works, specifically, "propositional conceptual works". They are abstract works constituted at least in part by propositional information (propositional information is information which has a truth value in some context).
Works of literature are textual, an abstract work whose propositional content is expressed, at least in substantial part, in text. Positive examples include novels, articles, resumes, and restaurant menus. Negative examples include episodes of a TV show. Works of literature may include non-textual components which expand on or otherwise contribute to the propositional content of the work, but the propositional content of the text could, alternatively, be expressed entirely in text.
Literature is assumed to be published. This means that the work has been produced for distribution, or is something which bears information which has been produced for distribution. Note that "published" here does not mean "printed and physically distributed", since intangible information-bearing things can be published using the World Wide Web, or broadcast on the airwaves.
Works of Art are physical objects that are a work, or a reproduction of a work, in one of the representational or plastic arts, such as a painting, sculpture, quilting, or stained glass composition. Works of art do not include plays, movies, music, performance art, or other activities. Works of art are considered to be a type of information-bearing object, but they need not have any propositional content. Examples include the Statue of Liberty, the Mona Lisa, a poster reproduction of Van Gogh's 'Starry Night', Rodin's 'Burghers of Calais', a piece of Ju ware from the Sung Dynasty, and the windows of Chartres Cathedral.
Human Activities are activities performed either by individual persons or by groups of people (such as organizations). Cyc contains thousands of concepts from this very broad collection. Examples include: dancing (and 24 subcategories, such as Irish step dancing), plowing a field, fly fishing (and several other kinds of fishing and hundreds of other leisure activities), speaking, sneezing (along with about 20 other involuntary bodily actions), meeting someone (along with thousands of other social occurrences), etc. Each of these concepts is deeply connected into the overall lattice of concepts, and each is used in facts and rules that contribute to Cyc's ability to reason about our world.
Language is a generative system of signs for transmitting information. These signs are normally conventional and arbitrary in nature, though the case of body language is a (borderline) exception to this. The reality of any given language consists in its being interpretable by some community (usually human). This is not quite true of computer languages, however such languages are only possible insofar as some kind of automation of the process of interpretation (by computers) has been effected. In the case of dead languages, the community may no longer exist (although even if no one can speak such languages any longer, currently-interpretable texts often remain, for example, the Attic Greek dialect). Languages are most often spoken, but not always (i.e. Sign Language).
Not every system of signs is a language; a certain richness of possible expression is required. Thus Morse Code, for example, though a convention for communication, is not a language. Finally, the concept of language is not intended to cover the special vocabulary and usages of a scientific, professional or other group, or a characteristic style of speech or writing (e.g. 'Shakespearean language').
It's worth noting that the possibility of a language which is in principle not interpretable by a community but only by a single individual is not a philosophically uncontentious issue. However certain influential arguments have been presented against it (see in particular Ludwig Wittgenstein, Philosophical Investigations).
Software is dealt with in a few different ways in Cyc. Two salient senses of software are:
As a kind of propositional conceptual work, software, or a specific computer program, is a deliberately created abstract object comprised of propositions that together constitute a list of instructions for computers to execute. Examples include Emacs (the program) and the Linux kernel (the program). Computer programs are distinct from computer code and from both running and installed programs. The instructions that comprise a computer program can be expressed as abstract computer code, but no list of instructions expressed in code constitutes a computer program as a conceptual work. Rather, the code in which a computer program is expressed constitutes an abstract information structure that can be related to the program it expresses. More than one computer code can express the same computer program; for example, a single computer program can be written in source code in several different computer languages, or it can be compiled as a binary executable. A physical computer program is called a "computer program copy" which is an information-bearing thing. A computer program that is being executed is called a "running computer process".
As an object, software is either a versioned or unversioned non-series software object, such as a program, a version of a program, a software package, or a library. Positive examples include Netscape Navigator, Netscape Navigator version 4.76, glibc, and SUNWzip. Negative examples include Netscape Navigator versions 3 through 4 inclusive, which is a series.
Mechanical Devices are physical devices which have at least one part that moves with respect to another one of its parts. Thus a spoon is not a mechanical device, but a pair of scissors is, as are more complex devices such as vacuum cleaners and the Challenger Space Shuttle.
Electrical Devices are powered devices that require an input of electrical current (as its energy source) in order to perform its intended function(s). Electrical devices include both complex devices (for example, stereo systems or computers) and simpler ones (for example, electrical components). Some non-examples are wagon, door knocker, ball, rowboat, and bicycle.
Astronomy: Cyc has some knowledge of astronomy from the standpoint of an amateur, but it also knows that astronomy is a scientific discipline encompassing a variety of areas of study. Cyc knows about planets and stars and formations of stars, and it knows the relative size of celestial objects compared with other objects.
Constellations are celestial regions which are normally distinguished by a particular asterism that is intended to depict some object. The celestial sphere is completely covered with constellations, which do not overlap. This is the more formal notion of 'constellation' used by astronomers. Examples include Ursa Major and Orion. Cyc also knows about asterisms, which is the more informal notion of 'constellation'.
Archaeoastronomy is the study of ancient astronomical theory and practice. There are both academic/scientific and non-scientific versions of this study. The former is essentially a subfield of Archaeology.
Cyc is also aware of what we call "Simple Astronomy", what any educated person should know about the sun, moon, planets, etc.
The concept of vehicle is thought of in two ways in Cyc: as a kind of transportation device and as a relationship between an event and a vehicle used to transport something in that event.
As a kind of transportation device, it is assumed that it moves under its own power. Examples include jet airplanes and automobiles; non-examples include skateboards, gliders, and rowboats. Note that hand-pushed power lawnmowers, even though they are self-powered devices, are not considered to be vehicles (as a kind of transportation device), since they must be pushed in order to remain in motion.
As a relationship between transportation events and transportation devices, vehicle is used to mean that the transportation device is both the provider of motive force and the transporter in the event. If an object is a vehicle in this sense and plays the role of transporter in some moving event, then it generally will play the role of vehicle in that event. Examples: a car plays the role of vehicle in driving. Note, however, that a bicycle does not play the role of vehicle in bike riding since it is not a provider of motive force. A borderline non-example is someone sitting in a car while it's being pulled by a tow truck; the car is not playing the role of vehicle in that event (because it is not the provider of motive force - the tow truck is).
A Building is a (usually large) fixed structure with walls and a roof, and with some inside area or areas designed to be occupied by humans (but not necessarily as a residence). Examples include the Empire State Building, Hearst Castle, an aircraft hangar at O'Hare, a light house in the Mediterranean Sea, the Sydney Opera House, and the Washington Monument in Washington, DC.
Weapons are primarily designed as instruments for physically harming or destroying animals (often humans), buildings, or other constructed artifacts. Weapons include swords, portable guns, bombs, and Napalm. Also included are various types of military hardware used to kill, destroy, or immobilize. Note that in the case of weapons which are 'fired' or otherwise distributed, both the launcher and the unit of ammunition are considered weapons in this sense. E.g. a bow, an arrow, a missile launcher, an ICBM, a weapons-grade sprayer, a cloud of mustard gas, a gun, and a bullet are all weapons. Non-artifacts and artifacts designed for some other purpose (as a found rock or brick) may be "used as" weapons, but are not weapons themselves.
The Solar System is the region of the universe near the sun that includes the sun, the eight known major planets and their moons or satellites, and objects such as asteroids and comets that travel in independent orbits. Cyc also knows about planetary systems in general, any group of celestial bodies moving in orbit around a central star or stars, so the Solar System is a specific planetary system which includes the earth's sun. Cyc knows the difference between earth, the soil, and Earth, the planet.
Cyc contains both general and domain-specific knowledge. Here are some domain-specific rules that make use of Cyc's general knowledge about the world.
Chemistry: If salts are created in some type of chemical reaction, then some type of base is involved in that reaction.
Computer Security: If a computer network implements IEEE 802.11 Wireless LAN Protocol and some computer is a node in that computer network, then that computer is vulnerable to decryption.
Healthcare: If an HMO provides coverage under some insurance plan, and the HMO provides "group" coverage (i.e., the coverage is provided via a "group" plan), and the insurance plan covers some medical care event, and the medical care event is performed as a service by some healthcare provider, then either the health care provider is a listed ("in-service") provider for the HMO, or the health care provider performs the medical care event as the result of a referral (sanctioned by the HMO).
Cyc contains some of the kinds of facts you'd typically find in a database, with two important differences:
All facts are tied to concepts in the knowledge base. For example, Cyc knows several hundred musicians, but it is more than a list. Since Cyc knows there are approximately 85 types things that Cyc knows every musician is. So, "Bruce Springsteen" isn't just a string in a list of data. Cyc knows that he is a person, a professional, a social being, and many other things.
Cyc can access facts that are stored in external structured sources (such as relational databases) and treat them as if they are assertions in the knowledge base. Using Semantic Knowledge Source Integration (SKSI), Cyc automatically constructs queries to issue to these data sources, and the returned data is properly associated with concepts in the Cyc ontology.
Stuff about living things
Stuff about cars and planes and trains and boats
Information about cows and stuff
Collections in Cyc are natural kinds or classes, as opposed to mathematical sets; their instances have some common attribute(s). Each collection is like a set in so far as it may have elements, subsets, and supersets, and may not have parts or spatial or temporal properties. Sets, however, differ from collections in that a mathematical set may be an arbitrary set of things which have nothing in common. In contrast, the instances of a collection will all have in common some feature(s), some 'intensional' qualities. In addition, two collections can be co-extensional (i.e., have all the same instances)