pOTTR: Incrementally building a template library

1. Introduction

In this chapter will incrementally build a set of templates that model the domain of mobile phone with the goal of representing the design of the phone, i.e., which parts different models of phone consist of, and the specific parts a specific phone (individual) consists of.

The reader should know the basics of OTTR.

In this chapter you will learn:

How to incrementally build a template library using a top-down modelling approach
How to use base templates as a design and validation tool while modelling
How to refine high-level templates into more precise, reusable definitions
How to populate a template library with concrete instances

1.1. Prefixes

The following prefixes are used throughout the document, and may be used in the text input areas of the interactive examples without declaration.

@prefix rdf: 	<http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: 	<http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: 	<http://www.w3.org/2002/07/owl#> .
@prefix xsd: 	<http://www.w3.org/2001/XMLSchema#> .
@prefix foaf: 	<http://xmlns.com/foaf/0.1/> .
@prefix dbp: 	<http://dbpedia.org/ontology/> .
@prefix ex: 	<http://example.com/ns#> .
@prefix ottr: 	<http://ns.ottr.xyz/0.4/> .
@prefix ax: 	<http://tpl.ottr.xyz/owl/axiom/0.1/> .
@prefix rstr: 	<http://tpl.ottr.xyz/owl/restriction/0.1/> .

2. Defining core patterns

Creating a signature

Based on the following instances, write a suitable signature for the template ex:Phone. Ignore for now that it is a base template, in the following exercises we will define it in more detail.

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string). ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none). ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

ex:Phone[<fill in>] :: BASE.

Extending the signature to a template

Use the templates below as well as existing OWL templates to create the ex:Phone template. Use ex:ConsistsOf as a black box (this template will be defined in the next exercise).

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string). ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none). ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

# ?name: the name of a particular class of phone # ?components: the list of components the phone consists of # ?label: an optional label # Pattern description: ?name is a subclass of ex:Phone and consists of # all components in ?components. It has an optional label ?label. ex:Phone[owl:Class ?name, NEList<owl:Class> ?components, ? xsd:string ?label] :: { # <fill in> } . # ?device: the name of the device # ?components: the components the device consists of ex:ConsistsOf[owl:Class ?device, NEList<owl:Class> ?components] :: BASE.

Solution

ex:Phone[owl:Class ?name, NEList<owl:Class> ?components, ? xsd:string ?label] :: {
  ax:SubClassOf(?name, ex:Phone),
  ottr:Triple(?name, rdfs:label, ?label),
  ex:ConsistsOf(?name, ?components)
}.

3. Refining incrementally

Add ConsistsOf

Use the ex:HasComponents and ex:OnlyComponents templates below to define the ex:ConsistsOf template. We will define ex:HasComponents and ex:OnlyComponents in the next exercise.

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string). ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none). ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

# ?device: the name of the class of device # ?components: the list of components ?device consists of # Pattern description: ?device consists of precisely the components in # ?components: it has one component from each class in ?components, # and any component ?device has must be from ?components ex:ConsistsOf[owl:Class ?device, NEList<owl:Class> ?components] :: { # <fill in> }. # indicates that ?item has a component from each of the classes in ?components ex:HasComponents[owl:Class ?item, NEList<owl:Class> ?components] :: BASE. # indicates that ?item only has components from the classes in ?components ex:OnlyComponents[owl:Class ?item, NEList<owl:Class> ?components] :: BASE. ### Previously defined: ex:Phone[owl:Class ?name, NEList<owl:Class> ?components, ? xsd:string ?label] :: { ax:SubClassOf(?name, ex:Phone), ottr:Triple(?name, rdfs:label, ?label), ex:ConsistsOf(?name, ?components) }.

Solution

ex:ConsistsOf[owl:Class ?item, NEList<owl:Class> ?components] :: {
  ex:HasComponents(?item, ?components),
  ex:OnlyComponents(?item, ?components)
}.

Add HasComponents and OnlyComponents

Use ex:HasComponent below as well as existing OWL and RDFS templates to define ex:HasComponents and ex:OnlyComponents. (Hint: look at rstr:ObjectUnionOf and ax:SubObjectAllValuesFrom).

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string). ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none). ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

# ?item: the name of a class of items # ?components: a list of component classes # Pattern description: ?item has a component from each of the classes in ?components ex:HasComponents[owl:Class ?item, NEList<owl:Class> ?components] :: { # <fill in> }. # ?item: the name of a class of items # ?components: a list of component classes # Pattern description: any component ?item is related to via # ex:hasComponent must come from the union of classes in ?components ex:OnlyComponents[owl:Class ?item, NEList<owl:Class> ?components] :: { # <fill in> }. ex:HasComponent[owl:Class ?item, owl:Class ?component] :: { ax:SubObjectSomeValuesFrom(?item, ex:hasComponent, ?component) }. ### Previously defined: ex:Phone[owl:Class ?name, NEList<owl:Class> ?components, ? xsd:string ?label] :: { ax:SubClassOf(?name, ex:Phone), ottr:Triple(?name, rdfs:label, ?label), ex:ConsistsOf(?name, ?components) }. ex:ConsistsOf[owl:Class ?item, NEList<owl:Class> ?components] :: { ex:HasComponents(?item, ?components), ex:OnlyComponents(?item, ?components) }.

Solution

ex:HasComponents[owl:Class ?item, NEList<owl:Class> ?components] :: {
  cross | ex:HasComponent(?item, ++?components)
}.

ex:OnlyComponents[owl:Class ?item, NEList<owl:Class> ?components] :: {
  rstr:ObjectUnionOf(_:b, ?components),
  ax:SubObjectAllValuesFrom(?item, ex:hasComponent, _:b)
}.

4. Instantiation

Add PhoneInstance

Now we are going to create a template for populating phone classes: ex:PhoneInstance. Define the template ex:PhoneInstance below.

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string). ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none). ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

# ?phoneInstance: the identifer for a specific phone # ?phone: a class of phones # ?components: a list of specific components # Pattern description: ?phoneInstance is of type ?phone and has the # components (i.e., is related to via ex:hasComponent) given in ?components. ex:PhoneInstance[owl:NamedIndividual ?phoneInstance, owl:Class ?phone, NEList<owl:NamedIndividual> ?components] :: { # <fill in> }. ### Previously defined: ex:Phone[owl:Class ?name, NEList<owl:Class> ?components, ? xsd:string ?label] :: { ax:SubClassOf(?name, ex:Phone), ottr:Triple(?name, rdfs:label, ?label), ex:ConsistsOf(?name, ?components) }. ex:ConsistsOf[owl:Class ?item, NEList<owl:Class> ?components] :: { ex:HasComponents(?item, ?components), ex:OnlyComponents(?item, ?components) }. ex:HasComponent[owl:Class ?item, owl:Class ?component] :: { ax:SubObjectSomeValuesFrom(?item, ex:hasComponent, ?component) }. ex:HasComponents[owl:Class ?item, NEList<owl:Class> ?components] :: { cross | ex:HasComponent(?item, ++?components) }. ex:OnlyComponents[owl:Class ?item, NEList<owl:Class> ?components] :: { rstr:ObjectUnionOf(_:b, ?components), ax:SubObjectAllValuesFrom(?item, ex:hasComponent, _:b) }.

Solution

ex:PhoneInstance[owl:NamedIndividual ?phoneInstance, owl:Class ?phone, NEList<owl:NamedIndividual> ?components] :: {
   ottr:Triple(?phoneInstance, rdf:type, ?phone),
   cross | ottr:Triple(?phoneInstance, ex:hasComponent, ++?components)
}.

Instantiation

Create one or more new phone classes and populate them with specific phones.

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string). ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none). ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

### Previously defined: ex:PhoneInstance[owl:NamedIndividual ?phoneInstance, owl:Class ?phone, NEList<owl:NamedIndividual> ?components] :: { ottr:Triple(?phoneInstance, rdf:type, ?phone), cross | ottr:Triple(?phoneInstance, ex:hasComponent, ++?components) }. ex:Phone[owl:Class ?name, NEList<owl:Class> ?components, ? xsd:string ?label] :: { ax:SubClassOf(?name, ex:Phone), ottr:Triple(?name, rdfs:label, ?label), ex:ConsistsOf(?name, ?components) }. ex:ConsistsOf[owl:Class ?item, NEList<owl:Class> ?components] :: { ex:HasComponents(?item, ?components), ex:OnlyComponents(?item, ?components) }. ex:HasComponent[owl:Class ?item, owl:Class ?component] :: { ax:SubObjectSomeValuesFrom(?item, ex:hasComponent, ?component) }. ex:HasComponents[owl:Class ?item, NEList<owl:Class> ?components] :: { cross | ex:HasComponent(?item, ++?components) }. ex:OnlyComponents[owl:Class ?item, NEList<owl:Class> ?components] :: { rstr:ObjectUnionOf(_:b, ?components), ax:SubObjectAllValuesFrom(?item, ex:hasComponent, _:b) }.

@prefix rdf: 	<http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: 	<http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: 	<http://www.w3.org/2002/07/owl#> .
@prefix xsd: 	<http://www.w3.org/2001/XMLSchema#> .
@prefix foaf: 	<http://xmlns.com/foaf/0.1/> .
@prefix dbp: 	<http://dbpedia.org/ontology/> .
@prefix ex: 	<http://example.com/ns#> .
@prefix ottr: 	<http://ns.ottr.xyz/0.4/> .
@prefix ax: 	<http://tpl.ottr.xyz/owl/axiom/0.1/> .
@prefix rstr: 	<http://tpl.ottr.xyz/owl/restriction/0.1/> .

ex:Phone(ex:Nokia3310, (ex:Screen, ex:HardCase, ex:CPU), "indestructible"^^xsd:string).
ex:Phone(ex:SamsungS9, (ex:CurvedScreen, ex:FastCPU), none).
ex:Phone(ex:iPhone8, (ex:RetinaScreen, ex:OtherFastCPU, ex:FPReader), "iphone"^^xsd:string).

5. Appendix

5.1. WebLutra

The web application that drives the interactive examples in this primer, called WebLutra, uses Lutra, the reference application for OTTR. Both applications are open source and available at http://gitlab.com/ottr/lutra/lutra. If you experience errors or have suggestions for improvements, please take a look at existing issues or file a new issue: http://gitlab.com/ottr/lutra/lutra/issues

Table of Contents

Incrementally building a template library

1. Introduction

1.1. Prefixes

2. Defining core patterns

Solution

3. Refining incrementally

Solution

Solution

4. Instantiation

Solution

5. Appendix

5.1. WebLutra