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The Product Types Ontology: Class Definition for "Nth root"

This page is part of http://www.productontology.org/, a huge, precise dictionary of product types and brand names for marking up Web sites with schema.org or the GoodRelations e-commerce standard.

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http://www.productontology.org/

On this page: Usage(schema.org/Microdata, RDFa, Facebook) Contact Information Caching Policy License Acknowledgments References

pto:Nth_root (rdf:type owl:Class)

URI http://www.productontology.org/id/Nth_root
rdfs:subClassOf gr:ProductOrService, http://schema.org/Product
rdfs:label Nth root (as a class or brand name of products of services)
Translation(s):  Wortelgetal@af;  جذر نوني@ar;  Kökaltı@az;  Корань (матэматыка)@be;  Коренуване@bg;  N-তম মূল@bn;  Изагуур (математика)@bxr;  Arrel enèsima@ca;  ڕەگی nەم@ckb; 

rdfs:comment

In mathematics, taking the nth root is an operation involving two numbers, the radicand and the index or degree. Taking the nth root is written as \sqrt{x}, where is the radicand and n is the index (also sometimes called the degree). This is pronounced as "the nth root of x". The definition then of an nth root of a number x is a number r (the root) which, when raised to the power of the positive integer n, yields x: A root of degree 2 is called a square root (usually written without the n as just \sqrt{x}) and a root of degree 3, a cube root (written \sqrt{x}). Roots of higher degree are referred by using ordinal numbers, as in fourth root, twentieth root, etc. The computation of an th root is a root extraction. For example, 3 is a square root of 9, since 3= 9, and −3 is also a square root of 9, since (−3)= 9. Any non-zero number considered as a complex number has different complex th roots, including the real ones (at most two). The th root of 0 is zero for all positive integers since . In particular, if is even and is a positive real number, one of its th roots is real and positive, one is negative, and the others (when ) are non-real complex numbers; if is even and is a negative real number, none of the th roots are real. If is odd and is real, one th root is real and has the same sign as while the other roots are not real. Finally, if is not real, then none of its th roots are real. Roots of real numbers are usually written using the radical symbol or radix \sqrt{{~^~}^~\!\!}, with \sqrt{x} denoting the positive square root of if is positive; for higher roots, \sqrt{x} denotes the real th root if is odd, and the positive nth root if is even and is positive. In the other cases, the symbol is not commonly used as being ambiguous. When complex th roots are considered, it is often useful to choose one of the roots, called principal root, as a principal value. The common choice is to choose the principal th root of as the th root with the greatest real part, and when there are two (for real and negative), the one with a positive imaginary part. This makes the th root a function that is real and positive for real and positive, and is continuous in the whole complex plane, except for values of that are real and negative. A difficulty with this choice is that, for a negative real number and an odd index, the principal th root is not the real one. For example, -8 has three cube roots, -2, 1 + i\sqrt{3} and 1 - i\sqrt{3}. The real cube root is -2 and the principal cube root is 1 + i\sqrt{3}. An unresolved root, especially one using the radical symbol, is sometimes referred to as a surd or a radical. Any expression containing a radical, whether it is a square root, a cube root, or a higher root, is called a radical expression, and if it contains no transcendental functions or transcendental numbers it is called an algebraic expression. The positive root of a number is the inverse operation of exponentiation with positive integer exponents. Roots can also be defined as special cases of exponentiation, where the exponent is a fraction: Roots are used for determining the radius of convergence of a power series with the root test. The th roots of 1 are called roots of unity and play a fundamental role in various areas of mathematics, such as number theory, theory of equations, and Fourier transform. (Source: Wikipedia, the free encyclopedia, see http://en.wikipedia.org/wiki/Nth_root)

Note: The extraction of the abstract from the Wikipedia page may sometimes yield imperfect results. We are improving the algorithm regularly.

is rdfs:domain of gr:category gr:color gr:condition gr:depth gr:hasEAN_UCC-13 gr:hasGTIN-14 gr:hasMPN gr:hasManufacturer gr:hasStockKeepingUnit gr:height gr:isAccessoryOrSparePartFor gr:isConsumableFor gr:isSimilarTo gr:weight gr:width
is rdfs:range of gr:includes gr:isAccessoryOrSparePartFor gr:isConsumableFor gr:isSimilarTo

Note: This is a generic list. Some of the properties may not be applicable to this particular type of object.

Trademark Disclaimer:  Since this service returns class descriptions for potentiall any series of characters, it cannot indicate automatically whether a name is a registered trademark or otherwise protected. We assume no liability for the absence of trademark rights and other damages. See the section "License" below for details.

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Usage

The following shows how to model that you offer to sell [a/an/some] Nth root for $ 19.99.

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Microdata / Use with http://schema.org/Product

One of the most powerful usages of the class definitions from this site is to describe the type of your page and product for the schema.org product markup in Microdata syntax much more precisely.

Simply add the full URI of a class from this site, e.g. http://www.productontology.org/id/Nth_root as an additional type as follows:

<div itemscope itemtype="http://schema.org/Product">
    <link itemprop="additionalType" href="http://www.productontology.org/id/Nth_root" />
    <!-- other schema.org properties go in here -->
</div>		

Note: In HTML5, it is valid to use the <link> element in the body of a HTML document.

Here is a complete example:

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
    <title>An offer to sell a / some Nth_root</title>
</head>
<body>
<div itemscope itemtype="http://schema.org/Product" itemid="#product">
    <link itemprop="additionalType" href="http://www.productontology.org/id/Nth_root" />
    <span itemprop="name">.. a short name for the object ...</span>
    Product description: 
    <span itemprop="description">... a longer description ...</span>
    <div itemprop="offers" itemscope itemtype="http://schema.org/Offer" itemid="#offer">
        <span itemprop="price">$19.99</span> 
        <link itemprop="availability" href="http://schema.org/InStock" />In stock
    </div>
</div>
</body>
</html>

Turtle Syntax

@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix pto: <http://www.productontology.org/id/> .
@prefix gr: <http://purl.org/goodrelations/v1#> .
@prefix foo: <http://example.com/> .

# The object
foo:myObject a <http://www.productontology.org/id/Nth_root> ;
	a gr:SomeItems ;
	gr:name "... a short name for the object ..."@en ;
	gr:description "... a longer description ..."@en .

# The agent (person or company) who is offering it
foo:ACMECorp a gr:BusinessEntity ;
	gr:legalName "ACME Corp" ;
	gr:offers foo:Offer .
		
# The offer to sell it
foo:Offer a gr:Offering ;
	gr:includes foo:myObject;
	foaf:page <http://URI_of_the_page_containing_the_offer.com>;
	gr:hasBusinessFunction gr:Sell ;
	gr:validFrom "2011-01-24T00:00:00+01:00"^^xsd:dateTime ;
	gr:validThrough "2011-12-24T00:00:00+01:00"^^xsd:dateTime ;
	gr:hasPriceSpecification
         [ a gr:UnitPriceSpecification ;
           gr:hasCurrency "USD"^^xsd:string ;
           gr:hasCurrencyValue "19.99"^^xsd:float ;
           gr:validThrough "2011-12-24T00:00:00+01:00"^^xsd:dateTime ] .

Note: Replace gr:SomeItems (http://purl.org/goodrelations/v1#SomeItems) by gr:Individual if you are describing a unique object of that kind (e.g. antique furniture).

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RDFa

<!DOCTYPE html>
<html version="HTML+RDFa 1.1" xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
    <title>An offer to sell a / some Nth_root</title>
</head>
<body>
<div xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
     xmlns:foaf="http://xmlns.com/foaf/0.1/"
     xmlns:gr="http://purl.org/goodrelations/v1#"
     xmlns:pto="http://www.productontology.org/id/"
     xmlns:foo="http://example.com/"
     xmlns:xsd="http://www.w3.org/2001/XMLSchema#">

<!-- The agent (person or company) who is offering it -->
   <div about="#ACMECorp" typeof="gr:BusinessEntity">
      <div property="gr:legalName">ACME Corp</div>
      <div rel="gr:offers">
<!-- The offer to sell it -->	
         <div about="#offer" typeof="gr:Offering">
            <div rel="gr:hasBusinessFunction" resource="http://purl.org/goodrelations/v1#Sell"></div>
            <div rel="gr:includes">
<!-- The object -->	
               <div about="#myObject" typeof="http://www.productontology.org/id/Nth_root">
                  <div rel="rdf:type" resource="http://purl.org/goodrelations/v1#SomeItems"></div>
                  <div property="gr:description" xml:lang="en">... a longer description ...</div>
                  <div property="gr:name" xml:lang="en">.. a short name for the object ...</div>
               </div>
            </div>
            <div rel="foaf:page" resource="http://URI_of_the_page_containing_the_offer"></div>
            <div rel="gr:hasPriceSpecification">
               <div typeof="gr:UnitPriceSpecification">
                  <div property="gr:hasCurrency" content="USD" datatype="xsd:string">$ </div>
                  <div property="gr:hasCurrencyValue" datatype="xsd:float">19.99</div>
                  <div property="gr:validThrough" content="2011-12-24T00:00:00+01:00" 
					   datatype="xsd:dateTime"></div>
               </div>
            </div>
            <div property="gr:validFrom" content="2011-01-24T00:00:00+01:00"
                 datatype="xsd:dateTime"></div>
            <div property="gr:validThrough" content="2011-12-24T00:00:00+01:00"
                 datatype="xsd:dateTime"></div>
         </div>
      </div>
   </div>
</div>
</body>
</html>

Note: Replace gr:SomeItems (http://purl.org/goodrelations/v1#SomeItems) by gr:Individual if you are describing a unique object of that kind (e.g. antique furniture).

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RDF/XML

<?xml version="1.0" encoding="UTF-8" ?>
<rdf:RDF xmlns:gr="http://purl.org/goodrelations/v1#" 
  xmlns:pto="http://www.productontology.org/id/" 
  xmlns:xsd="http://www.w3.org/2001/XMLSchema#" 
  xmlns:foaf="http://xmlns.com/foaf/0.1/" 
  xmlns:foo="http://example.com/" 
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<!-- The object -->
  <rdf:Description rdf:about="http://example.com/myObject">
    <rdf:type rdf:resource="http://www.productontology.org/id/Nth_root"/>    
    <rdf:type rdf:resource="http://purl.org/goodrelations/v1#SomeItems"/>
    <gr:name xml:lang="en">... a short name for the object ...</gr:name>
    <gr:description xml:lang="en">... a longer description ...</gr:description>
  </rdf:Description>
<!-- The agent (person or company) who is offering it -->
  <gr:BusinessEntity rdf:about="http://example.com/ACMECorp">
    <gr:legalName>ACME Corp</gr:legalName>
    <gr:offers rdf:resource="http://example.com/Offer" />
  </gr:BusinessEntity>
<!-- The offer to sell it -->   
  <gr:Offering rdf:about="http://example.com/Offer">
    <gr:includes rdf:resource="http://example.com/myObject" />
    <foaf:page rdf:resource="http://URI_of_the_page_containing_the_offer"/>
    <gr:hasBusinessFunction rdf:resource="http://purl.org/goodrelations/v1#Sell"/>
    <gr:validFrom rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">
      2011-01-24T00:00:00+01:00</gr:validFrom>
    <gr:validThrough rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">
      2011-12-24T00:00:00+01:00</gr:validThrough>
    <gr:hasPriceSpecification>
      <gr:UnitPriceSpecification>
        <gr:hasCurrency rdf:datatype="http://www.w3.org/2001/XMLSchema#string">USD</gr:hasCurrency>
        <gr:hasCurrencyValue rdf:datatype="http://www.w3.org/2001/XMLSchema#float">19.99</gr:hasCurrencyValue>
        <gr:validThrough rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">
          2011-12-24T00:00:00+01:00</gr:validThrough>
      </gr:UnitPriceSpecification>
    </gr:hasPriceSpecification>
  </gr:Offering>

</rdf:RDF>

Note: Replace gr:SomeItems (http://purl.org/goodrelations/v1#SomeItems) by gr:Individual if you are describing a unique object of that kind (e.g. antique furniture).

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SPARQL Query

prefix foaf: <http://xmlns.com/foaf/0.1/> 
prefix xsd: <http://www.w3.org/2001/XMLSchema#> 
prefix pto: <http://www.productontology.org/id/> 
prefix gr: <http://purl.org/goodrelations/v1#> 
prefix foo: <http://example.com/> 

# Find the cheapest offer for a Nth_root

SELECT * WHERE{
?company gr:offers ?offer .
?offer a gr:Offering .
?offer gr:hasBusinessFunction gr:Sell .
OPTIONAL {?offer rdfs:label ?label } .
OPTIONAL {?offer gr:name ?label } .
OPTIONAL {?offer rdfs:comment ?label } .
OPTIONAL {?offer gr:description ?label } .
?offer gr:hasPriceSpecification ?p .
?p a gr:UnitPriceSpecification .
?p gr:hasCurrency ?currency .
?p gr:hasCurrencyValue ?price .
?offer gr:includes ?product .
?product a <http://www.productontology.org/id/Nth_root> .
}
ORDER BY (?price)
LIMIT 10

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Facebook Open Graph Protocol

You can also use the class definitions from this site for better describing the type of your page or product for the Facebook Open Graph Protocol.

Simply define the namespace prefix pto: in the <html> element of your page

<html version="HTML+RDFa 1.1" 
	xmlns="http://www.w3.org/1999/xhtml" 
	xmlns:pto="http://www.productontology.org/id/" 
	>

and use the compact URI (CURIE) pto:Nth_root in combination with og:type as follows:

	<meta property="og:type" content="pto:Nth_root"/>

A complete example is here.

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Contact Information

Univ.-Prof. Dr. Martin Hepp

E-Business and Web Science Research Group
Chair of General Management and E-Business
Universität der Bundeswehr München
Werner-Heisenberg-Weg 39
D-85579 Neubiberg, Germany

Phone: +49 89 6004-4217
eMail: mhepp(at)computer.org (preferred mode of communication)
Web: http://www.heppnetz.de/
Web: http://www.unibw.de/ebusiness/

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Caching Policy

In order to minimize the load on the Wikipedia API, all requests are cached internally for 72 hours. This means that changes to the English Wikipedia will be available in this service within 72 hours or less if the same entry has been requested before. Classes not requested within the last six hours are always guaranteed to be in sync with the latest version in Wikipedia.

The RDF/XML dump file is updated every 12 hours only.

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License

The class definition text is taken from Wikipedia, the free encyclopedia under a Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) license. Accordingly, the ontology class definitions are available under the very same license.

Trademark Disclaimer:  Since this service returns class descriptions for potentially any series of characters, it cannot indicate automatically whether a name is a registered trademark or otherwise protected. If you want us to block a certain name, please send your request including proof of your rights on the name to our contact address listed below.. Any of the trademarks, service marks, collective marks, design rights or similar rights that are mentioned, used, or cited in this service are the property of their respective owners. Their use here does not imply that you may use them for any purpose other than for the same or a similar informational use as contemplated by the original authors of the underlying Wikipedia articles under the CC-BY-SA and GFDL licensing schemes. Productontology.org is neither endorsed by nor affiliated with any of the holders of any such rights and as such cannot grant any rights to use any otherwise protected materials. Your use of any such or similar incorporeal property is at your own risk.

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Acknowledgements

Thanks to Stefano Bertolo, Julien Chaumond, Bob Ferris, Kingsley Idehen, Axel Polleres, Andreas Radinger, Alex Stolz, and Giovanni Tummarello for very valuable feedback, and to Katharina Siorpaes and Daniel Bachlechner, who contributed to the initial analysis of the stability of Wikipedia URIs back in 2007.

The work on The Product Types Ontology has been supported by the German Federal Ministry of Research (BMBF) by a grant under the KMU Innovativ program as part of the Intelligent Match project (FKZ 01IS10022B).

BMBF logo

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References

Wikipedia: Nth root, available at http://en.wikipedia.org/wiki/Nth_root.

Hepp, Martin: GoodRelations: An Ontology for Describing Products and Services Offers on the Web, Proceedings of the 16th International Conference on Knowledge Engineering and Knowledge Management (EKAW2008), Acitrezza, Italy, September 29 - October 3, 2008, Springer LNCS, Vol 5268, pp. 332-347.

Hepp, Martin; Siorpaes, Katharina; Bachlechner, Daniel: Harvesting Wiki Consensus: Using Wikipedia Entries as Vocabulary for Knowledge Management, IEEE Internet Computing, Vol. 11, No. 5, pp. 54-65, Sept-Oct 2007.

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