]> 2009/04/07 OpenCyc Knowledge Base Copyright© 2001-2009 Cycorp, Inc., http://www.cyc.com/, Austin, TX, USA This file contains an OWL representation of information contained in the OpenCyc Knowledge Base. The content of this OWL file is licensed under the Creative Commons Attribution 3.0 license whose text can be found at http://creativecommons.org/licenses/by/3.0/legalcode. The content of this OWL file, including the OpenCyc content it represents, constitutes the "Work" referred to in the Creative Commons license. The terms of this license equally apply to, without limitation, renamings and other logically equivalent reformulations of the content of this OWL file (or portions thereof) in any natural or formal language, as well as to derivations of this content or inclusion of it in other ontologies. Mappings between OpenCyc terms and Wikipedia article names provided by Olena Medelyan and Catherine Legg, University of Waikato, NZ under a Creative Commons Attribution 3.0 license. externalID A unique, language-neutral, variable-sized identifier for a concept that can be used to refer unambiguously to that concept across OWL exports or across Cyc inference engines. label A natural-language representation for a concept that is both human readable and readable by the Cyc inference engine. These terms are not guaranteed to refer to the same concept across time but are guaranteed to be consistent within a particular OWL export. Use 'cycAnnot:externalID' for unambiguously referring to a concept across OWL exports or across Cyc inference engines. Pressure A specialization of <a href="http://sw.opencyc.org/concept/Mx4rhywBFkT6EdaAAACgye4oEQ" class="cyc_term">PhysicalQuantity</a>. Each instance of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> is a specific measure of a force exerted on some surface. Degrees of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> may be represented using <a href="http://sw.opencyc.org/concept/Mx4rvyorqJwpEbGdrcN5Y29ycA" class="cyc_term">GenericValueFunction</a>s or with qualitative collections (e.g., <a href="http://sw.opencyc.org/concept/Mx4rvVkJQJwpEbGdrcN5Y29ycA" class="cyc_term">BruisingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkI-5wpEbGdrcN5Y29ycA" class="cyc_term">FracturingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkIvJwpEbGdrcN5Y29ycA" class="cyc_term">ImperceptiblePressure</a>). Indicate the <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> of a particular fluid with the predicate <a href="http://sw.opencyc.org/concept/Mx4rvViRRJwpEbGdrcN5Y29ycA" class="cyc_term">fluidPressure</a> (q.v.); indicate atmospheric pressure with <a href="http://sw.opencyc.org/concept/Mx4rvVihb5wpEbGdrcN5Y29ycA" class="cyc_term">barometricPressure</a> (q.v.). pressure pressures Pressure http://en.wikipedia.org/wiki/Pressure http://www.w3.org/2006/03/wn/wn20/instances/synset-pressure-noun-1 pressure of which some gas has a barometric pressure (SubcollectionOfWithRelationFromTypeFn Pressure barometricPressure GaseousTangibleThing) systolic SystolicPressure DiastolicPressure diastolic The collection of all air pressure. A type of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a>. The collection <a href="http://sw.opencyc.org/concept/Mx4rvViQv5wpEbGdrcN5Y29ycA" class="cyc_term">AirPressure</a> is a <a href="http://sw.opencyc.org/concept/Mx4rvVja4JwpEbGdrcN5Y29ycA" class="cyc_term">DerivedMeasurableQuantityType</a> and a <font color="#ff0000">#$UnitOfMeasureCollection</font>. AirPressure air pressure light pressure LightPressure Pressure in an amount not uncomfortable or painful to humans when felt on most body parts; e.g., pressure of clothing that fits, of a gentle touch, or of mild winds. Pressure in an amount that would quickly bruise a human being; e.g., pressure of a blow or of a very heavy weight. BruisingPressure bruising pressure MediumPressure Pressure in an amount that is noticeable but not painful on most parts of the human body; e.g., weight of a daypack or a heavy winter coat. medium pressure Pressure in an amount below human sensitivity to pressure. Humans do not detect pressures less than .85 g/mm.sq. imperceptible pressure ImperceptiblePressure FracturingPressure fracturing pressure Pressure in an amount that would fracture human bone; e.g., pressure of a hard blow, collision, or explosion. heavy pressure HeavyPressure Pressure in an amount that is at least uncomfortable and eventually painful to humans. A specialization of <a href="http://sw.opencyc.org/concept/Mx4rhywBFkT6EdaAAACgye4oEQ" class="cyc_term">PhysicalQuantity</a> (q.v.). This is the collection of quanitative physical features that <i>only</i> tangible objects can have. Specializations include <a href="http://sw.opencyc.org/concept/Mx4rvgC7-5wpEbGdrcN5Y29ycA" class="cyc_term">Rigidity</a> and <a href="http://sw.opencyc.org/concept/Mx4rvVjULZwpEbGdrcN5Y29ycA" class="cyc_term">Dirtiness</a>. Conversely, physical quantity-types such as <a href="http://sw.opencyc.org/concept/Mx4rvVjDAZwpEbGdrcN5Y29ycA" class="cyc_term">Area</a> and <a href="http://sw.opencyc.org/concept/Mx4rvViRs5wpEbGdrcN5Y29ycA" class="cyc_term">Speed</a> are <i>not</i> specializations of <a href="http://sw.opencyc.org/concept/Mx4rygxStLLcQdecMqyUNVYD1g" class="cyc_term">TangiblePhysicalQuantity</a>, as they can also characterize (e.g.) intangible <a href="http://sw.opencyc.org/concept/Mx4rvlxdi5wpEbGdrcN5Y29ycA" class="cyc_term">SpaceRegion</a>s and <a href="http://sw.opencyc.org/concept/Mx4rwQCA9ZwpEbGdrcN5Y29ycA" class="cyc_term">WavePropagation</a> events, respectively. tangible physical quantity TangiblePhysicalQuantity Wikipedia Article URL (<a href="http://sw.opencyc.org/concept/Mx4rNv0nbm4TTjOp7yhmnzOyqg" class="cyc_term">wikipediaArticleURL</a> THING URL) means that in <a href="http://sw.opencyc.org/concept/Mx4rtqXA6OC8QdiWC72DuLJdUw" class="cyc_term">Wikipedia_WebSite</a> THING is described by an article located at URL wikipediaArticleURL seeAlsoURI <code>(<a href="http://sw.opencyc.org/concept/Mx4riWVFR6HJSpaEaHrcWS3MSA" class="cyc_term">seeAlsoURI</a> <b>THING</b> <b>URI</b>)</code> means that a description of the resource identified by URI is likely to contain information pertinent to THING. This predicate is roughly equivalent to rdfs:seeAlso. See Also URI Pressure A specialization of <a href="http://sw.opencyc.org/concept/Mx4rhywBFkT6EdaAAACgye4oEQ" class="cyc_term">PhysicalQuantity</a>. Each instance of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> is a specific measure of a force exerted on some surface. Degrees of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> may be represented using <a href="http://sw.opencyc.org/concept/Mx4rvyorqJwpEbGdrcN5Y29ycA" class="cyc_term">GenericValueFunction</a>s or with qualitative collections (e.g., <a href="http://sw.opencyc.org/concept/Mx4rvVkJQJwpEbGdrcN5Y29ycA" class="cyc_term">BruisingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkI-5wpEbGdrcN5Y29ycA" class="cyc_term">FracturingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkIvJwpEbGdrcN5Y29ycA" class="cyc_term">ImperceptiblePressure</a>). Indicate the <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> of a particular fluid with the predicate <a href="http://sw.opencyc.org/concept/Mx4rvViRRJwpEbGdrcN5Y29ycA" class="cyc_term">fluidPressure</a> (q.v.); indicate atmospheric pressure with <a href="http://sw.opencyc.org/concept/Mx4rvVihb5wpEbGdrcN5Y29ycA" class="cyc_term">barometricPressure</a> (q.v.). pressure type of atemporal collection in which membership is necessarily essential AtemporalNecessarilyEssentialCollectionType A collection of collections. Each instance <code><b>COL</b></code> of <a href="http://sw.opencyc.org/concept/Mx4rqEYnNVMqEdaSKAACs0x8nw" class="cyc_term">AtemporalNecessarilyEssentialCollectionType</a> (<i>ANECT</i>) is a collection satisfying three conditions: (1) <code><b>COL</b></code> is disjoint with (see <a href="http://sw.opencyc.org/concept/Mx4rvViA45wpEbGdrcN5Y29ycA" class="cyc_term">disjointWith</a>) <a href="http://sw.opencyc.org/concept/Mx4rvViAxJwpEbGdrcN5Y29ycA" class="cyc_term">TemporalThing</a>, (2) every instance <code><b>INST</b></code> of <code><b>COL</b></code> is an instance of <code><b>COL</b></code> essentially (i.e. <code><b>INST</b></code> is an instance of <code><b>COL</b></code>, and could not exist without being an instance of <code><b>COL</b></code>), and (3) condition (2) is a necessary truth about <code><b>COL</b></code>. <p/> Positive examples of ANECTs include <a href="http://sw.opencyc.org/concept/Mx4rvViAzJwpEbGdrcN5Y29ycA" class="cyc_term">Collection</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVieEpwpEbGdrcN5Y29ycA" class="cyc_term">Integer</a>, and <a href="http://sw.opencyc.org/concept/Mx4rvViAzZwpEbGdrcN5Y29ycA" class="cyc_term">Relation</a> (each of which is a collection of atemporals and is such that, necessarily, all of its instances are in it essentially). Negative examples include <a href="http://sw.opencyc.org/concept/Mx4rvVjpUZwpEbGdrcN5Y29ycA" class="cyc_term">SpatialThing</a> (though arguably it is necessary that all of its instances are essentially instances of it, it is not disjoint with <a href="http://sw.opencyc.org/concept/Mx4rvViAxJwpEbGdrcN5Y29ycA" class="cyc_term">TemporalThing</a>) and <a href="http://sw.opencyc.org/concept/Mx4rwP4FM5wpEbGdrcN5Y29ycA" class="cyc_term">UniqueAnatomicalPartType</a> (which, though disjoint with <a href="http://sw.opencyc.org/concept/Mx4rvViAxJwpEbGdrcN5Y29ycA" class="cyc_term">TemporalThing</a>, has instances, such as <a href="http://sw.opencyc.org/concept/Mx4rvVjvDpwpEbGdrcN5Y29ycA" class="cyc_term">Heart</a>, that could exist even if they weren't instances of it; e.g. it might have been the case that every creature with a heart had at least two hearts). There are no known examples of Cyc-reified collections satisfying conditions (1) and (2) but not (3), but one can be contrived. Suppose that all of today's winning lottery numbers were primes. Now consider the collection: <p/> (<a href="http://sw.opencyc.org/concept/Mx4rvrhK-JwpEbGdrcN5Y29ycA" class="cyc_term">CollectionUnionFn</a> (<a href="http://sw.opencyc.org/concept/Mx4rvVjkdpwpEbGdrcN5Y29ycA" class="cyc_term">TheSet</a> <a href="http://sw.opencyc.org/concept/Mx4rvVjrdZwpEbGdrcN5Y29ycA" class="cyc_term">PrimeNumber</a> <i>TodaysWinningLotteryNumbers</i>)) <p/> This collection is clearly disjoint with <a href="http://sw.opencyc.org/concept/Mx4rvViAxJwpEbGdrcN5Y29ycA" class="cyc_term">TemporalThing</a> and, by hypothesis, all of its instances are in it essentially (as each prime number is essentially a prime number). But this last fact is not <i>necessarily</i> true of this collection: the collection might have had instances that belonged to it only contingently (i.e. not essentially), as it might have been the case that one of today's winning lottery numbers was non-prime, and no number is such that it is essentially one of today's winning lottery numbers. <p/> When asserting that something is an instance or specialization of a given instance of ANECT, it is appropriate to do so in the <a href="http://sw.opencyc.org/concept/Mx4r3_SgQU2iEdaCwAACs0x8nw" class="cyc_term">UniversalVocabularyMt</a> (q.v.). Indeed, ANECT was specially defined to facilitate the movement of appropriate assertions to that microtheory. <p/> Cf. <a href="http://sw.opencyc.org/concept/Mx4rGeylLJTfEdqAAAACs0uFOQ" class="cyc_term">PragmaticallyDecontextualizedCollection</a>. type of quantity QuantityType A <a href="http://sw.opencyc.org/concept/Mx4rHQdVmB_TEdaAAABQ2rksLw" class="cyc_term">SecondOrderCollection</a> and a specialization of <a href="http://sw.opencyc.org/concept/Mx4rvVirnZwpEbGdrcN5Y29ycA" class="cyc_term">ObjectType</a>. Each instance of <a href="http://sw.opencyc.org/concept/Mx4rvVkDZJwpEbGdrcN5Y29ycA" class="cyc_term">QuantityType</a> is a specialization of <a href="http://sw.opencyc.org/concept/Mx4rSGNLQK45EdqAAAACs6hRXg" class="cyc_term">Quantity</a> (q.v.). Notable specializations of <a href="http://sw.opencyc.org/concept/Mx4rvVkDZJwpEbGdrcN5Y29ycA" class="cyc_term">QuantityType</a> include <a href="http://sw.opencyc.org/concept/Mx4rwF4t15wpEbGdrcN5Y29ycA" class="cyc_term">TotallyOrderedQuantityType</a> and <a href="http://sw.opencyc.org/concept/Mx4rvVjVk5wpEbGdrcN5Y29ycA" class="cyc_term">UnorderedQuantityType</a>. Pretty String (<a href="http://sw.opencyc.org/concept/Mx4rwLSVCpwpEbGdrcN5Y29ycA" class="cyc_term">prettyString</a> TERM STRING) means that STRING is the English word or expression (sequence of words) commonly used to refer to TERM. The predicate <a href="http://sw.opencyc.org/concept/Mx4rwLSVCpwpEbGdrcN5Y29ycA" class="cyc_term">prettyString</a> is used by the code which generates CycL to English paraphrases, but its applicability is not restricted to this use. prettyString UnitOfMeasureConcept A <a href="http://sw.opencyc.org/concept/Mx4ret7qgOKgEdmAAAACs6hfSg" class="cyc_term">ConceptTypeByDomain</a> (q.v.). Instances of <a href="http://sw.opencyc.org/concept/Mx4rC-8cJgBpEdqAAAACs0uFOQ" class="cyc_term">UnitOfMeasureConcept</a> are collections and relations having to do with unit of measurement functions and the kinds of quantities they return as values. Important specializations and instances of <a href="http://sw.opencyc.org/concept/Mx4rvViAqpwpEbGdrcN5Y29ycA" class="cyc_term">UnitOfMeasure</a>, major specializations or <a href="http://sw.opencyc.org/concept/Mx4rvViAp5wpEbGdrcN5Y29ycA" class="cyc_term">ScalarInterval</a>, and relations that are important to measurement theory are instances of this collection. unit of measure concept Pressure A specialization of <a href="http://sw.opencyc.org/concept/Mx4rhywBFkT6EdaAAACgye4oEQ" class="cyc_term">PhysicalQuantity</a>. Each instance of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> is a specific measure of a force exerted on some surface. Degrees of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> may be represented using <a href="http://sw.opencyc.org/concept/Mx4rvyorqJwpEbGdrcN5Y29ycA" class="cyc_term">GenericValueFunction</a>s or with qualitative collections (e.g., <a href="http://sw.opencyc.org/concept/Mx4rvVkJQJwpEbGdrcN5Y29ycA" class="cyc_term">BruisingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkI-5wpEbGdrcN5Y29ycA" class="cyc_term">FracturingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkIvJwpEbGdrcN5Y29ycA" class="cyc_term">ImperceptiblePressure</a>). Indicate the <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> of a particular fluid with the predicate <a href="http://sw.opencyc.org/concept/Mx4rvViRRJwpEbGdrcN5Y29ycA" class="cyc_term">fluidPressure</a> (q.v.); indicate atmospheric pressure with <a href="http://sw.opencyc.org/concept/Mx4rvVihb5wpEbGdrcN5Y29ycA" class="cyc_term">barometricPressure</a> (q.v.). pressure A <a href="http://sw.opencyc.org/concept/Mx4rAmoSCGJbQdiSXZJvYiNhkQ" class="cyc_term">CycVocabularyTopic</a> and a <a href="http://sw.opencyc.org/concept/Mx4rtGXkHpNaEdqAAAACs0uFOQ" class="cyc_term">KBDependentCollection</a>. WeatherAttributes-Weather-Topic weather attributes weather topic MultiDimensionalQuantity A specialization of <a href="http://sw.opencyc.org/concept/Mx4rr-2NGp7sQdidoL5VyxYMGg" class="cyc_term">MeasurableQuantity</a> (q.v.). Each instance of <a href="http://sw.opencyc.org/concept/Mx4rU9w69qCIQdiaX7o2wbs-og" class="cyc_term">MultiDimensionalQuantity</a> is a measurable quantity that is defined as the product or ratio of other quantities. For example, (<a href="http://sw.opencyc.org/concept/Mx4rvVkDkZwpEbGdrcN5Y29ycA" class="cyc_term">MilesPerHour</a> 65) is a multi-dimensional quantity obtainable by dividing (<a href="http://sw.opencyc.org/concept/Mx4rvVi3VJwpEbGdrcN5Y29ycA" class="cyc_term">Mile</a> 65) by (<a href="http://sw.opencyc.org/concept/Mx4rvVjrNJwpEbGdrcN5Y29ycA" class="cyc_term">HoursDuration</a> 1), and (<a href="http://sw.opencyc.org/concept/Mx4rvViQA5wpEbGdrcN5Y29ycA" class="cyc_term">CubicMeter</a> 8) is a derived quantity obtainable by multiplying (<a href="http://sw.opencyc.org/concept/Mx4rvVjRp5wpEbGdrcN5Y29ycA" class="cyc_term">Meter</a> 2) by itself twice. In contrast, (<a href="http://sw.opencyc.org/concept/Mx4rvVi3VJwpEbGdrcN5Y29ycA" class="cyc_term">Mile</a> 65), (<a href="http://sw.opencyc.org/concept/Mx4rvVjrNJwpEbGdrcN5Y29ycA" class="cyc_term">HoursDuration</a> 1), and (<a href="http://sw.opencyc.org/concept/Mx4rvVjRp5wpEbGdrcN5Y29ycA" class="cyc_term">Meter</a> 2) are all instances of <a href="http://sw.opencyc.org/concept/Mx4rUstvYKCIQdiBWaekaRIs-w" class="cyc_term">OneDimensionalQuantity</a> (cf.). <p/> Each multi-dimensional quantity is in principle equal to the result of applying some (reified or otherwise) <a href="http://sw.opencyc.org/concept/Mx4rVG-MSJ_AQdiKntlmhkDKfQ" class="cyc_term">MultiDimensionalUnitOfMeasure</a> (q.v.) to some number or other <a href="http://sw.opencyc.org/concept/Mx4rnVZQSiCmEdaAAACgyZzFrg" class="cyc_term">NumericInterval</a> (or pair of numeric-intervals). <p/> When a <i>one-dimensional</i> quantity is multiplied or divided by another one-dimensional quantity, the result is always a multi-dimensional quantity. But note that this is <i>not</i> true of the results of multiplying and dividing quantities generally. For example, (<a href="http://sw.opencyc.org/concept/Mx4rwHa2CZwpEbGdrcN5Y29ycA" class="cyc_term">ProductFn</a> (<a href="http://sw.opencyc.org/concept/Mx4rvVkDkZwpEbGdrcN5Y29ycA" class="cyc_term">MilesPerHour</a> 65) (<a href="http://sw.opencyc.org/concept/Mx4rvVjrNJwpEbGdrcN5Y29ycA" class="cyc_term">HoursDuration</a> 1)) is equal to the one-dimensional quantity (<a href="http://sw.opencyc.org/concept/Mx4rvVi3VJwpEbGdrcN5Y29ycA" class="cyc_term">Mile</a> 65).) <p/> Specializations of <a href="http://sw.opencyc.org/concept/Mx4rU9w69qCIQdiaX7o2wbs-og" class="cyc_term">MultiDimensionalQuantity</a> include <a href="http://sw.opencyc.org/concept/Mx4rVQ8MvqCIQdicLoOa1pZefg" class="cyc_term">TwoDimensionalQuantity</a> and <a href="http://sw.opencyc.org/concept/Mx4r-7GRzKCIQdiHEaxh2Wf1-g" class="cyc_term">ThreeDimensionalQuantity</a>. multi dimensional quantity Pressure A specialization of <a href="http://sw.opencyc.org/concept/Mx4rhywBFkT6EdaAAACgye4oEQ" class="cyc_term">PhysicalQuantity</a>. Each instance of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> is a specific measure of a force exerted on some surface. Degrees of <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> may be represented using <a href="http://sw.opencyc.org/concept/Mx4rvyorqJwpEbGdrcN5Y29ycA" class="cyc_term">GenericValueFunction</a>s or with qualitative collections (e.g., <a href="http://sw.opencyc.org/concept/Mx4rvVkJQJwpEbGdrcN5Y29ycA" class="cyc_term">BruisingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkI-5wpEbGdrcN5Y29ycA" class="cyc_term">FracturingPressure</a>, <a href="http://sw.opencyc.org/concept/Mx4rvVkIvJwpEbGdrcN5Y29ycA" class="cyc_term">ImperceptiblePressure</a>). Indicate the <a href="http://sw.opencyc.org/concept/Mx4rvVjtE5wpEbGdrcN5Y29ycA" class="cyc_term">Pressure</a> of a particular fluid with the predicate <a href="http://sw.opencyc.org/concept/Mx4rvViRRJwpEbGdrcN5Y29ycA" class="cyc_term">fluidPressure</a> (q.v.); indicate atmospheric pressure with <a href="http://sw.opencyc.org/concept/Mx4rvVihb5wpEbGdrcN5Y29ycA" class="cyc_term">barometricPressure</a> (q.v.). pressure attributes of materials material topic AttributesOfMaterials-Material-Topic wikipediaArticleName (<a href="http://sw.opencyc.org/concept/Mx4rTv-jk9SPTXa991kk5mAvHg" class="cyc_term">wikipediaArticleName</a> THING NAME) means that in <a href="http://sw.opencyc.org/concept/Mx4rtqXA6OC8QdiWC72DuLJdUw" class="cyc_term">Wikipedia_WebSite</a> THING is described by an article with the title NAME Wikipedia Article Name A specialization of <a href="http://sw.opencyc.org/concept/Mx4rU9w69qCIQdiaX7o2wbs-og" class="cyc_term">MultiDimensionalQuantity</a> (q.v.). Each instance of <a href="http://sw.opencyc.org/concept/Mx4rhFtvNGqnQdeLusO9k_GjYA" class="cyc_term">RatioQuantity</a> is a quantity that is derivable (via <a href="http://sw.opencyc.org/concept/Mx4rvViAq5wpEbGdrcN5Y29ycA" class="cyc_term">QuotientFn</a>) as a ratio of other quantities. For example, (<a href="http://sw.opencyc.org/concept/Mx4rvVkDkZwpEbGdrcN5Y29ycA" class="cyc_term">MilesPerHour</a> 65) is a ratio quantity obtainable by dividing (<a href="http://sw.opencyc.org/concept/Mx4rvVi3VJwpEbGdrcN5Y29ycA" class="cyc_term">Mile</a> 65) by (<a href="http://sw.opencyc.org/concept/Mx4rvVjrNJwpEbGdrcN5Y29ycA" class="cyc_term">HoursDuration</a> 1); and (<a href="http://sw.opencyc.org/concept/Mx4rvViqP5wpEbGdrcN5Y29ycA" class="cyc_term">PoundsPerSquareInch</a> 50) is equal to <p/> <pre> (<a href="http://sw.opencyc.org/concept/Mx4rvViAq5wpEbGdrcN5Y29ycA" class="cyc_term">QuotientFn</a> (<a href="http://sw.opencyc.org/concept/Mx4rvVjHs5wpEbGdrcN5Y29ycA" class="cyc_term">Pound_UnitOfForce</a> 50) (<a href="http://sw.opencyc.org/concept/Mx4rvVjPkpwpEbGdrcN5Y29ycA" class="cyc_term">SquaredFn</a> (<a href="http://sw.opencyc.org/concept/Mx4rvVihIJwpEbGdrcN5Y29ycA" class="cyc_term">Inch</a> 1))) . </pre> <p/> Ratio quantities are used for measuring a difference or change in one quantity against a (usually incremental) difference or change in another quantity. When the later quantity is a <a href="http://sw.opencyc.org/concept/Mx4rvViApZwpEbGdrcN5Y29ycA" class="cyc_term">Time_Quantity</a> (as in the first example above), the ratio quantity is an instance of the specialization <a href="http://sw.opencyc.org/concept/Mx4rvVjrwpwpEbGdrcN5Y29ycA" class="cyc_term">Rate</a>. <p/> See also <a href="http://sw.opencyc.org/concept/Mx4rv3YfGZwpEbGdrcN5Y29ycA" class="cyc_term">PerFn</a>. ratio quantity RatioQuantity