@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xml: <http://www.w3.org/XML/1998/namespace> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<http://purl.org/co/previousItem> a owl:FunctionalProperty, owl:ObjectProperty;
  rdfs:label "has previous item"@en;
  <http://www.w3.org/2004/02/skos/core#note> "Given the list (I[1], I[2], ... , I[i-1], I[i], I[i+1], ... , I[n-1], I[n]), the previous item of I[i] is I[i-1]."@en;
  rdfs:comment "The relation between an item and the previous item in a list."@en;
  rdfs:subPropertyOf <http://purl.org/co/precededBy>;
  owl:inverseOf <http://purl.org/co/nextItem>;
  <http://purl.org/vocab/vann/example> """
    :author-3 
        co:previousItem :author-2 .
    
    :author-2 
        co:previousItem :author-1 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/element> a owl:ObjectProperty;
  rdfs:label "has element"@en;
  rdfs:comment "The relation between a collection and the members of a collection"@en;
  rdfs:domain <http://purl.org/co/Collection>;
  owl:propertyChainAxiom _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-56F3602FC00214D2C29039FDD9BAEC5A;
  <http://purl.org/vocab/vann/example> """
    :reading-list a co:Set ;
        co:element :paper-1 , 
                :paper-2 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-609C6BCBFAAA974E1763A173CD5BF09C a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li1>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#li2>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/nextItem> .

<http://purl.org/co/lastItem> a owl:FunctionalProperty, owl:ObjectProperty;
  rdfs:label "has last item"@en;
  rdfs:comment "The relation between an item and the last item of the list."@en;
  rdfs:domain <http://purl.org/co/List>;
  rdfs:range _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6FB98B4823B59BEA41B42A0974475D34;
  rdfs:subPropertyOf <http://purl.org/co/item>;
  <http://purl.org/vocab/vann/example> """
    :authors a co:List ;
        co:lastItem :author-3 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-56AD56F06596A9BE66326CB31B6237CE rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-66F665B8CB745C91A4CD06ADA41E8B65;
  rdf:rest rdf:nil .

<http://purl.org/co/followedBy> a owl:ObjectProperty, owl:TransitiveProperty;
  rdfs:label "is followed by"@en;
  <http://www.w3.org/2004/02/skos/core#note> "Given the list (I[1], I[2], ... , I[i-1], I[i], I[i+1], ... , I[n-1], I[n]), the item I[i] is followed by I[i+1], ... , I[n-1] and I[n]."@en;
  rdfs:comment "The relation between an item and the following item in a list."@en;
  rdfs:domain <http://purl.org/co/ListItem>;
  rdfs:range <http://purl.org/co/ListItem>;
  <http://purl.org/vocab/vann/example> """
    :author-1 
        co:followedBy :author-2 , 
                :author-3 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-72B74618957ECBBB4E992F3B29D0DCEF rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-582497683D23452CA1AC76AD3B90ABE0;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-56AD56F06596A9BE66326CB31B6237CE .

<http://purl.org/dc/elements/1.1/title> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-14955C54D10DA0DA4EF2D2DC73F824AA a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#i>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#value>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-44E79561FF39882A0B8023DEB6504EFD a owl:Restriction;
  owl:cardinality "1"^^xsd:nonNegativeInteger;
  owl:onProperty <http://purl.org/co/index> .

<http://purl.org/co> a owl:Ontology;
  <http://purl.org/dc/elements/1.1/contributor> "Marco Ocana", "Sebastian Barzaghi (https://orcid.org/0000-0002-0799-1527)";
  <http://purl.org/dc/elements/1.1/creator> "Paolo Ciccarese (https://orcid.org/0000-0002-5156-2703)",
    "Silvio Peroni (http://orcid.org/0000-0003-0530-4305)";
  <http://purl.org/dc/elements/1.1/date> "2026-10-02";
  <http://purl.org/dc/elements/1.1/description> """
The **_Collections Ontology (CO)_** is an ontology for defining unordered collections (sets and bags) and ordered collections (or lists).

![The main architecture of CO.](co.png)

The main class of CO is `co:Collection`, i.e. a group of objects that can be considered as a whole. 
Each collection is linked to the objects it contains by means of the property `co:element` (with `co:elementOf` as its inverse), and to the number of objects it contains by means of the property `co:size`. 
A collection has exactly one size.

CO defines three kinds of collections:

- `co:Set`, an unordered collection that cannot contain duplicate elements;
- `co:Bag`, an unordered collection that can contain the same element more than once;
- `co:List`, a bag in which the elements are ordered.

Since the same object can be in a bag more than once, a bag is not only linked to its elements. 
Each occurrence of an object in a bag is a `co:Item`, and each list item in a list is a `co:ListItem`, which is a subclass of `co:Item`. 

![The representation of a set according to CO.](set.png)

A `co:Set` is the simplest collection of CO. 
A set is directly linked to each of its members by means of `co:element`. 
No item is necessary, since each object can be in a set only once. 
The size of a set is the number of its elements.

![The representation of a bag according to CO.](bag.png)

A `co:Bag` is linked to its items by means of `co:item`. 
Each `co:Item` is one occurrence of an object in the bag, and it is linked to that object by means of the functional property `co:itemContent`. 
An item cannot be the content of another item. 
Two items of the same bag can have the same content: this is how a bag contains duplicates.

The property chain `co:item o co:itemContent` is a subproperty of `co:element`. 
Thus, the elements of a bag are inferred from its items. 
The size of a bag is the number of its items, not the number of its distinct elements.

![The representation of a list according to CO.](list.png)

A `co:List` is a bag in which all the items are `co:ListItem`s.
A list has at most one first item (`co:firstItem`) and at most one last item (`co:lastItem`). 

Each list item has exactly one position in the list, starting from 1, specified by means of `co:index`. 
Each list item is linked to the list item that immediately follows it by means of `co:nextItem`, and to the list item that immediately precedes it by means of `co:previousItem`. 
The property chain `co:item o co:nextItem` is a subproperty of `co:item`. Thus, it is sufficient to specify the first item of a list and the chain of `co:nextItem` relations: all the other items of the list are inferred.

CO also includes some SWRL rules that complete the description of a list:

- the index of a list item is the index of its previous item plus one;
- two items of the same list with consecutive indexes are linked by `co:nextItem`;
- the item of a list with index 1 is the first item of the list;
- the size of a list is the index of its last item, and the item whose index is equal to the size of the list is the last item of the list;
- a list item that is preceded or followed by itself raises an error (`error:hasError`).

## Examples of use

In the following subsections, we introduce some examples to showcase how to use CO. 

The prefixes that are used in all the examples provided below are defined as follows:

        @prefix : <http://www.sparontologies.net/example/> .
        @prefix co: <http://purl.org/co/> .
        @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

### A reading list as a set

A reading list contains two papers. 
The order of the papers is not relevant and each paper is in the reading list only once. 
Thus, the reading list is a `co:Set` that is linked to its members with `co:element`.

        :reading-list a co:Set ;
            co:element :paper-1 , :paper-2 ;
            co:size \"2\"^^xsd:nonNegativeInteger .

### In-text citations as a bag

The text of an article cites `:paper-1` twice and `:paper-2` once. 
The order of the citations is not relevant, but the number of times each paper is cited is. 
Thus, the citations are a `co:Bag` of three `co:Item`s: each item is one occurrence, and `co:itemContent` links the item to the cited paper. 
The statements `:citations co:element :paper-1 , :paper-2` are inferred by means of the property chain `co:item o co:itemContent`.

        :citations a co:Bag ;
            co:item :citation-1 , 
                :citation-2 , 
                :citation-3 ;
            co:size \"3\"^^xsd:nonNegativeInteger .

        :citation-1 a co:Item ; 
                co:itemContent :paper-1 .

        :citation-2 a co:Item ; 
                co:itemContent :paper-2 .

        :citation-3 a co:Item ; 
                co:itemContent :paper-1 .

### The authors of a paper as a list

A paper has three authors, and their order is relevant. 
Thus, the authors are a `co:List` of three `co:ListItem`s. 
Each list item has a position (`co:index`), refers to one author (`co:itemContent`) and is linked to the list item that follows it (`co:nextItem`).

        :authors a co:List ;
            co:firstItem :author-1 ;
            co:item :author-1 , :author-2 , :author-3 ;
            co:lastItem :author-3 ;
            co:size \"3\"^^xsd:nonNegativeInteger .

        :author-1 a co:ListItem ;
            co:index \"1\"^^xsd:positiveInteger ;
            co:itemContent :alice ;
            co:nextItem :author-2 .

        :author-2 a co:ListItem ;
            co:index \"2\"^^xsd:positiveInteger ;
            co:itemContent :bob ;
            co:nextItem :author-3 .

        :author-3 a co:ListItem ;
            co:index \"3\"^^xsd:positiveInteger ;
            co:itemContent :carol .

## Competency Questions

CO can be used for answering several questions related to different ways entities can be grouped into aggregates and organized into collections.
In the following subsections, some of them are introduced together with their respective SPARQL queries. 

The prefixes that are used in all the SPARQL queries provided below are defined as follows:
        
        PREFIX : <http://www.sparontologies.net/example/>
        PREFIX co: <http://purl.org/co/>

### CQ1

What are the entities that belong to a collection?

        SELECT DISTINCT ?collection ?element
        WHERE {
            ?collection co:element|co:item/co:itemContent ?element .
        }

### CQ2

How many times does each entity appear in a bag?

        SELECT ?element (COUNT(?item) AS ?occurrences)
        WHERE {
            :citations co:item ?item .
            ?item co:itemContent ?element .
        }
        GROUP BY ?element

### CQ3

What is the size of a collection?

        SELECT ?collection ?size
        WHERE {
            ?collection co:size ?size .
        }

### CQ4

What are the first entity and the last entity of a list?

        SELECT ?first ?last
        WHERE {
            :authors co:firstItem/co:itemContent ?first ;
                co:lastItem/co:itemContent ?last .
        }

### CQ5

Which entity is at a given position of a list?

        SELECT ?element
        WHERE {
            :authors co:item ?item .
            ?item co:index ?index ;
                co:itemContent ?element .
            FILTER (?index = 2)
        }

    """@en;
  <http://purl.org/dc/elements/1.1/title> "The Collections Ontology (CO)"@en;
  owl:imports <http://purl.org/spar/error>;
  <http://purl.org/dc/terms/bibliographicCitation> "Ciccarese, P., & Peroni, S. (2014). The Collections Ontology: creating and handling collections in OWL 2 DL frameworks. Semantic Web, 5(6), 515-529. DOI: https://doi.org/10.3233/SW-130121.";
  <http://purl.org/dc/terms/created> "2012-03-12";
  <http://purl.org/dc/terms/issued> "2012-03-12";
  <http://purl.org/dc/terms/license> <http://creativecommons.org/licenses/by/4.0/>;
  <http://purl.org/dc/terms/modified> "2026-10-02";
  <http://purl.org/dc/terms/publisher> <https://ror.org/00wb4mk85>;
  <http://purl.org/dc/terms/source> <https://github.com/SPAROntologies/co/blob/master/docs/cq.md>;
  <http://purl.org/ontology/bibo/doi> "TBA";
  <http://purl.org/ontology/bibo/status> <http://purl.org/ontology/bibo/status/published>;
  <http://purl.org/vocab/vann/preferredNamespacePrefix> "co"@en;
  <http://purl.org/vocab/vann/preferredNamespaceUri> "http://purl.org/co"@en;
  owl:backwardCompatibleWith <https://raw.githubusercontent.com/collections-ontology/collections-ontology/refs/heads/master/collections.owl>;
  owl:priorVersion <https://raw.githubusercontent.com/collections-ontology/collections-ontology/refs/heads/master/collections.owl>;
  owl:versionIRI <http://purl.org/co/2026-10-02>;
  owl:versionInfo "2.1.0";
  <http://xmlns.com/foaf/0.1/logo> <https://github.com/SPAROntologies/co/blob/master/spar.png>;
  <https://schema.org/codeRepository> <https://github.com/SPAROntologies/co>;
  <https://schema.org/image> <https://github.com/SPAROntologies/co/blob/master/docs/current/co.png>,
    <https://github.com/SPAROntologies/co/blob/master/docs/current/set.png>, <https://github.com/SPAROntologies/co/blob/master/docs/current/bag.png>,
    <https://github.com/SPAROntologies/co/blob/master/docs/current/list.png>;
  <https://schema.org/includedInDataCatalog> <https://fairsharing.org/>;
  <https://schema.org/keywords> "bibliometrics"@en, "collections"@en, "scholarly publishing"@en,
    "scientometrics"@en, "semantic publishing"@en .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-ADD87F937DB0B202A699523C3185FBE1 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#current>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#r>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FB9FA8FBE78BF59942B8AEE42D1425F3 a owl:Restriction;
  owl:onProperty _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F352D6A3B78183CA56382F9CFF77AB63;
  owl:someValuesFrom <http://purl.org/co/Bag> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-886570297553720699846680D264E856 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li1>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#r1>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

<http://purl.org/co/index> a owl:DatatypeProperty;
  rdfs:label "has index"@en;
  rdfs:comment "A number identifying the position, starting from 1, of a particular list item within a list."@en;
  rdfs:domain <http://purl.org/co/ListItem>;
  rdfs:range xsd:positiveInteger;
  <http://purl.org/vocab/vann/example> """
    :author-2 a co:ListItem ;
        co:index \"2\"^^xsd:positiveInteger .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E47FF1BB992F6C6715B8DC6A244F5E53 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#i>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/lastItem> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A1C995FCC150E8C88C929909E92A2621 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li>;
  <http://www.w3.org/2003/11/swrl#argument2> "1";
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FAD0035D5058F905634764BA279E11A1 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#last>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#r>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E10194ADAF16F94E9DC175F48F1E0C6A a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A8539FEA030D6F88DE24018BB42D2879;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B2D77AECF68AB3978A5C4E03A1500D79 a owl:Restriction;
  owl:cardinality "0"^^xsd:nonNegativeInteger;
  owl:onProperty <http://www.essepuntato.it/2009/10/error/hasError> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-223BDC7A8120C2ADA987DCA80CBED519 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-7E6B09CF2EEA1B7F92916DB1B35E2182;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-32855EF68EFF07C397A97FC733574877 a rdf:List;
  rdf:first <urn:swrl#r1>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-39627A2D457151948F8AA51D465A7BF3 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-1923EA5B200CC0CDB259B0F002E0F058 rdf:first
    <http://purl.org/co/itemContent>;
  rdf:rest rdf:nil .

<http://purl.org/co/nextItem> a owl:FunctionalProperty, owl:ObjectProperty;
  rdfs:label "has next item"@en;
  <http://www.w3.org/2004/02/skos/core#note> "Given the list (I[1], I[2], ... , I[i-1], I[i], I[i+1], ... , I[n-1], I[n]), the next item of I[i] is I[i+1]."@en;
  rdfs:comment "The relation between an item and the next item in a list."@en;
  rdfs:subPropertyOf <http://purl.org/co/followedBy>;
  <http://purl.org/vocab/vann/example> """
    :author-1 
        co:nextItem :author-2 .

    :author-2 
        co:nextItem :author-3 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-9EBDD0A2D9208BB22CDAE8E352432CED a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FAD0035D5058F905634764BA279E11A1;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-09913E33201DE4563E94BCD24136AFA1 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-EB9936EA00B7B6D7741FA156C783E11A;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B167E356C1B2DC9F1D22A3BE821BDB2C a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#i>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/itemOf> .

<http://purl.org/co/lastItemOf> a owl:ObjectProperty;
  rdfs:label "is last item of"@en;
  rdfs:comment "The relation between an object and a list in which the object is last item."@en;
  rdfs:subPropertyOf <http://purl.org/co/itemOf>;
  owl:inverseOf <http://purl.org/co/lastItem>;
  <http://purl.org/vocab/vann/example> """
    :author-3 a co:ListItem ;
        co:lastItemOf :authors .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/ListItem> a owl:Class;
  rdfs:label "list item"@en;
  rdfs:comment "An element belonging to a list."@en;
  rdfs:subClassOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-44E79561FF39882A0B8023DEB6504EFD,
    <http://purl.org/co/Item>;
  <http://purl.org/vocab/vann/example> """
    :author-2 a co:ListItem ;
        co:itemOf :authors ;
        co:index \"2\"^^xsd:positiveInteger ;
        co:itemContent :bob ;
        co:previousItem :author-1 ;
        co:nextItem :author-3 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/Item> a owl:Class;
  rdfs:label "item"@en;
  rdfs:comment "An element belonging to a bag."@en;
  rdfs:subClassOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FB9FA8FBE78BF59942B8AEE42D1425F3,
    owl:Thing;
  <http://purl.org/vocab/vann/example> """
    :citation-1 a co:Item ;
        co:itemOf :citations ;
        co:itemContent :paper-1 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<urn:swrl#nextR> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-AE8A12578F5B4136C368F872AABCB0EA rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-D259B1B8AD5BCEC6FFF59A5640F37503;
  rdf:rest rdf:nil .

<http://www.essepuntato.it/2009/10/error/hasError> a owl:DatatypeProperty;
  rdfs:label "has error"@en;
  rdfs:comment "A description, usually in natural language, of which kind of error results from a resource."@en;
  rdfs:domain _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B2D77AECF68AB3978A5C4E03A1500D79;
  rdfs:isDefinedBy <http://purl.org/spar/error/>;
  rdfs:range xsd:string;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/firstItem> a owl:FunctionalProperty, owl:ObjectProperty;
  rdfs:label "has first item"@en;
  rdfs:comment "The relation between a list and the first item of the list."@en;
  rdfs:domain <http://purl.org/co/List>;
  rdfs:range _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-1F4A092D9533148FEDB1F04CF828BC1E;
  rdfs:subPropertyOf <http://purl.org/co/item>;
  <http://purl.org/vocab/vann/example> """
    :authors a co:List ;
        co:firstItem :author-1 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CFD3532FAEFAEE41EFCC64A59C064D23 a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BBFEDD7659E3CE87FB6E9DEFBCEFB124;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E176B6FEF0C7C61D41F57944F5A67341 .

<urn:swrl#li> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BCC55CD84CD50D82ED6E33A1F1F49EDE a rdf:List;
  rdf:first <urn:swrl#r2>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-32855EF68EFF07C397A97FC733574877 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6FB98B4823B59BEA41B42A0974475D34 a owl:Class;
  owl:intersectionOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6E58F44C50E235CB761B0D752068C524 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F0791A06356A28BFD031166AB53CB41E a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#current>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#next>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/nextItem> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F606D3C0486AAFE9CCFA06143A17442A a owl:Restriction;
  owl:cardinality "0"^^xsd:nonNegativeInteger;
  owl:onProperty <http://purl.org/co/nextItem> .

<http://purl.org/co/List> a owl:Class;
  rdfs:label "list"@en;
  rdfs:comment "An ordered array of items, that can be present in multiple copies"@en;
  rdfs:subClassOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A9AD7E0000681B91308F794136E5E1F0,
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-7F6C2F19005AD087A20F0A8C680D0FDF, _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-EA3869B04BE0B44B04084BCA77997811;
  <http://purl.org/vocab/vann/example> """
    :authors a co:List ;
        co:firstItem :author-1 ;
        co:item :author-1 , 
                :author-2 , 
                :author-3 ;
        co:lastItem :author-3 ;
        co:size \"3\"^^xsd:nonNegativeInteger .

    :author-1 a co:ListItem ;
        co:index \"1\"^^xsd:positiveInteger ;
        co:itemContent :alice ;
        co:nextItem :author-2 .

    :author-2 a co:ListItem ;
        co:index \"2\"^^xsd:positiveInteger ;
        co:itemContent :bob ;
        co:nextItem :author-3 .

    :author-3 a co:ListItem ;
        co:index \"3\"^^xsd:positiveInteger ;
        co:itemContent :carol .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/itemContentOf> a owl:ObjectProperty;
  rdfs:label "is item content of"@en;
  rdfs:comment "The relation between an object and the item that refers to the object."@en;
  owl:inverseOf <http://purl.org/co/itemContent>;
  <http://purl.org/vocab/vann/example> """
    :paper-1 
        co:itemContentOf :citation-1 , 
                :citation-3 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2E0A3480EB9BF07EB3FDCF22FEFC247B a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-ADD87F937DB0B202A699523C3185FBE1;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-09913E33201DE4563E94BCD24136AFA1 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BE16AA53582A29BEB751984C50ECC181 a rdf:List;
  rdf:first <urn:swrl#r>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-432D7F79851AD54344F11E81651434A6 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-66F665B8CB745C91A4CD06ADA41E8B65 a owl:Restriction;
  owl:onProperty <http://purl.org/co/lastItem>;
  owl:someValuesFrom <http://purl.org/co/Item> .

<http://purl.org/dc/elements/1.1/language> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-1F4A092D9533148FEDB1F04CF828BC1E a owl:Class;
  owl:intersectionOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-59B2046958D94B815880B3A28DACF548 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-432D7F79851AD54344F11E81651434A6 a rdf:List;
  rdf:first 1;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-13C2BBCA2161D0AE7DBC00AC9414670E a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-999E08649CD3314AA3D1B5A2CC32040E;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-DE189C1E074D8D3848977222C7BD865A rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A6479985D218C559F22D9A41227F9605;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BBFEDD7659E3CE87FB6E9DEFBCEFB124 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B167E356C1B2DC9F1D22A3BE821BDB2C;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FDFA7E34669D1C9C87F1C92FF7172E7B .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E7DD7C4537664949651B4E00EB858E49 rdf:first
    <http://purl.org/co/List>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-72B74618957ECBBB4E992F3B29D0DCEF .

<urn:swrl#li1> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-12C3CB18F726892C8BBC10B6C442E1D7 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#x>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#x>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/followedBy> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-030144B5784BC6F90572503838F24B58 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A1C995FCC150E8C88C929909E92A2621;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-32E40DE5FEC624F0A2C4498413433099 rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C0F82A7EF0FFA291B64888EC83C7501F;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CFB83611103492F150290102EBF11D86 a owl:Class;
  rdfs:subClassOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-631A5B9F9EA151E7E7D18D6EE2FF159F;
  owl:intersectionOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-35CCE8355F0C6A4C0C70477FA670228D .

<http://purl.org/co/itemContent> a owl:FunctionalProperty, owl:ObjectProperty;
  rdfs:label "has item content"@en;
  rdfs:comment "The relation between an item and the actual resource to which the item refers."@en;
  rdfs:domain <http://purl.org/co/Item>;
  rdfs:range _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-55199DA6A7100E6FA61B77FF271F92A0;
  <http://purl.org/vocab/vann/example> """
    :citation-1 a co:Item ;
        co:itemContent :paper-1 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/itemOf> a owl:ObjectProperty;
  rdfs:label "is item of"@en;
  rdfs:comment "The relation between an item and a bag in which the item is member."@en;
  owl:inverseOf <http://purl.org/co/item>;
  <http://purl.org/vocab/vann/example> """
    :citation-1 a co:Item ;
        co:itemOf :citations .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/Bag> a owl:Class;
  rdfs:label "bag"@en;
  rdfs:comment "Collection that can have a number of copies of each object"@en;
  rdfs:subClassOf <http://purl.org/co/Collection>;
  owl:disjointWith <http://purl.org/co/Set>;
  <http://purl.org/vocab/vann/example> """
    :citations a co:Bag ;
        co:item :citation-1 , 
                :citation-2 , 
                :citation-3 ;
        co:size \"3\"^^xsd:nonNegativeInteger .

    :citation-1 a co:Item ; 
        co:itemContent :paper-1 .

    :citation-2 a co:Item ; 
        co:itemContent :paper-2 .

    :citation-3 a co:Item ; 
        co:itemContent :paper-1 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/size> a owl:DatatypeProperty;
  rdfs:label "has size"@en;
  <http://www.w3.org/2004/02/skos/core#note> """
CO defines the size of a collection as the sum of the number of times entities that are part of the collection appear in it. This means that co:size considers how much each entity is involved by a particular collection, i.e.:
- the size of the set {a, b, c} is three;
- the size of the bag [a, a, b, b, b, c] is five;
- the size of the list (a, b, c, b, a, b, c, c) is seven."""@en;
  rdfs:comment "The number of items belonging to a collection."@en;
  rdfs:domain <http://purl.org/co/Collection>;
  rdfs:range xsd:nonNegativeInteger;
  <http://purl.org/vocab/vann/example> """
    :reading-list a co:Set ;
        co:element :paper-1 , 
                :paper-2 ;
        co:size \"2\"^^xsd:nonNegativeInteger .

    :citations a co:Bag ;
        co:item :citation-1 , 
                :citation-2 , 
                :citation-3 ;
        co:size \"3\"^^xsd:nonNegativeInteger .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2B1EECB9E88B39720522EEE95CC67ED1 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CD8385CEFF6EDAB8EAA676147AAE9FA0;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C4C3A1D4F14C2B9668F6DFAB08B89C75 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6E26184613E3AC3FEBD9D711BFAD8310 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#value>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/size> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CD9B877E2BC0A8550F00D1A923E266D6 a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-11394B32B00650FE9B5A07A3E2A0DBE4;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FC8AC90E2A29158A85D911564C1BFF94 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-18C0147F97554E12EDB9C6D8A867980A a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-29DB50B4B4B2E8F22BC1D6AFE7B49FE9;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-030144B5784BC6F90572503838F24B58 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F8A6CBC8ACC96D6A4DDBFAB11FA7A25A a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#value>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/size> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CA858F7BEDB54ED4060B0BE1B6C3BBDC a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-D827B630E0C081B548136A6F3BDDB72E;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-DC2CD85E4331B4B147BF6A4FD35D84C4 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-7F6C2F19005AD087A20F0A8C680D0FDF a owl:Class;
  owl:intersectionOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-7C5CFFB48726ECC6B525C38A2A88769B .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-99D10F43CAF594E8A0755AD04E92199D a owl:Restriction;
  owl:cardinality "0"^^xsd:nonNegativeInteger;
  owl:onProperty <http://purl.org/co/previousItem> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-4F9B6CAAF5790C8333125A1AC4A97F00 a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-18C0147F97554E12EDB9C6D8A867980A;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-223BDC7A8120C2ADA987DCA80CBED519 .

<http://purl.org/co/Collection> a owl:Class;
  rdfs:label "collection"@en;
  rdfs:comment "A group of objects that can be considered as a whole."@en;
  rdfs:subClassOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A43860B8890A48249BE1A0780B16CAB1,
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-5774F0AAEB37A416EE1AF3448E4E3310, owl:Thing;
  owl:disjointWith <http://purl.org/co/Item>;
  <http://purl.org/vocab/vann/example> """
    :reading-list a co:Collection ;
        co:element :paper-1 , 
                :paper-2 ;
        co:size \"2\"^^xsd:nonNegativeInteger .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-160606A77AA0EF0C73E3F7FF4266C582 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li1>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/itemOf> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FC8AC90E2A29158A85D911564C1BFF94 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-9EF8947B404891F2A3267A8D8B6C7E23;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CDCE3EA76670FEDE85EBDE07BC79DE3D a <http://www.w3.org/2003/11/swrl#BuiltinAtom>;
  <http://www.w3.org/2003/11/swrl#arguments> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BCC55CD84CD50D82ED6E33A1F1F49EDE;
  <http://www.w3.org/2003/11/swrl#builtin> <http://www.w3.org/2003/11/swrlb#add> .

<urn:swrl#x> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-AB09CB30E01D451CD0719CAAC3F02FCF a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li2>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#r2>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CDC97E6847249B7140009BC073F43CAC a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CDCE3EA76670FEDE85EBDE07BC79DE3D;
  rdf:rest rdf:nil .

<http://purl.org/co/precededBy> a owl:ObjectProperty, owl:TransitiveProperty;
  rdfs:label "is preceded by"@en;
  <http://www.w3.org/2004/02/skos/core#note> "Given the list (I[1], I[2], ... , I[i-1], I[i], I[i+1], ... , I[n-1], I[n]), the item I[i] is preceded by I[i-1], ... , I[2] and I[1]."@en;
  rdfs:comment "The relation between an item and the preceding item in a list."@en;
  owl:inverseOf <http://purl.org/co/followedBy>;
  <http://purl.org/vocab/vann/example> """
    :author-3 
        co:precededBy :author-2 , 
                :author-1 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<urn:swrl#r2> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-9EF8947B404891F2A3267A8D8B6C7E23 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#next>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#nextR>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-EB9936EA00B7B6D7741FA156C783E11A a <http://www.w3.org/2003/11/swrl#BuiltinAtom>;
  <http://www.w3.org/2003/11/swrl#arguments> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B1637248847EEDA9EC63591E08A1B50B;
  <http://www.w3.org/2003/11/swrl#builtin> <http://www.w3.org/2003/11/swrlb#add> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-29DB50B4B4B2E8F22BC1D6AFE7B49FE9 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/itemOf> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-06B660F759B902D403249D7AF04C6033 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#x>;
  <http://www.w3.org/2003/11/swrl#argument2> "A list item cannot be followed by itself";
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://www.essepuntato.it/2009/10/error/hasError> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C18574881F027A3A9E60A4A98FEDFC3B a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6E26184613E3AC3FEBD9D711BFAD8310;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E176B6FEF0C7C61D41F57944F5A67341 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E47FF1BB992F6C6715B8DC6A244F5E53;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-5774F0AAEB37A416EE1AF3448E4E3310 a owl:Restriction;
  owl:allValuesFrom owl:Thing;
  owl:onProperty <http://purl.org/co/element> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CF0E26D3502D9901715D4207091A7187 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-8EB5C46088CB1536D71AC765B8F9A10F;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B4000EB4EC5233E361BD14D20E4FD433 a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2B1EECB9E88B39720522EEE95CC67ED1;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-13C2BBCA2161D0AE7DBC00AC9414670E .

<http://purl.org/co/elementOf> a owl:ObjectProperty;
  rdfs:label "is element of"@en;
  rdfs:comment "The relation between an object and a collection in which the object is member."@en;
  owl:inverseOf <http://purl.org/co/element>;
  <http://purl.org/vocab/vann/example> """
    :paper-1 
        co:elementOf :reading-list .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BA766C97D497D0DFF1FA4E22340E922B a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-DD3EAA90F10DBF6DCE365B9AA1F6CAA3;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-47A2B25D5E24B63C8B698004361DA0A4 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#list>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#last>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/lastItem> .

<http://purl.org/co/item> a owl:ObjectProperty;
  rdfs:label "has item"@en;
  rdfs:comment "The relation between a bag and every item of the bag"@en;
  rdfs:domain <http://purl.org/co/Bag>;
  rdfs:range <http://purl.org/co/Item>;
  owl:propertyChainAxiom _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-09C8B46C2440CFB0E22DBF1A9799CBBA;
  <http://purl.org/vocab/vann/example> """
    :citations a co:Bag ;
        co:item :citation-1 , 
                :citation-2 , 
                :citation-3 .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

<http://purl.org/co/Set> a owl:Class;
  rdfs:label "set"@en;
  rdfs:comment "A collection that cannot contain duplicate elements."@en;
  rdfs:subClassOf <http://purl.org/co/Collection>;
  <http://purl.org/vocab/vann/example> """
    :reading-list a co:Set ;
        co:element :paper-1 , 
                :paper-2 ;
        co:size \"2\"^^xsd:nonNegativeInteger .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A6479985D218C559F22D9A41227F9605 a owl:Restriction;
  owl:onProperty <http://purl.org/co/item>;
  owl:someValuesFrom <http://purl.org/co/ListItem> .

<http://purl.org/dc/elements/1.1/publisher> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-DC2CD85E4331B4B147BF6A4FD35D84C4 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-06B660F759B902D403249D7AF04C6033;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-999E08649CD3314AA3D1B5A2CC32040E a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#i>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#value>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/index> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2997177C617B2D4BE4F4CF34C3ECAF4B rdf:first
    <http://purl.org/co/nextItem>;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-EA3869B04BE0B44B04084BCA77997811 a owl:Restriction;
  owl:maxCardinality "1"^^xsd:nonNegativeInteger;
  owl:onProperty <http://purl.org/co/firstItem> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-11394B32B00650FE9B5A07A3E2A0DBE4 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F0791A06356A28BFD031166AB53CB41E;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2E0A3480EB9BF07EB3FDCF22FEFC247B .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CD8385CEFF6EDAB8EAA676147AAE9FA0 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#i>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/lastItem> .

<http://purl.org/dc/elements/1.1/format> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C0A9668B27DFA633FA02DF5A53CD0A0E a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-609C6BCBFAAA974E1763A173CD5BF09C;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FDFA7E34669D1C9C87F1C92FF7172E7B a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-14955C54D10DA0DA4EF2D2DC73F824AA;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C18574881F027A3A9E60A4A98FEDFC3B .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FDB6E226C5EFDC2EC698AB1A4F22E74A a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6C01F90CE6B9300EA13BF357D00FAF55;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BA766C97D497D0DFF1FA4E22340E922B .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C0F82A7EF0FFA291B64888EC83C7501F a owl:Restriction;
  owl:allValuesFrom <http://purl.org/co/ListItem>;
  owl:onProperty <http://purl.org/co/item> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A8539FEA030D6F88DE24018BB42D2879 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#x>;
  <http://www.w3.org/2003/11/swrl#argument2> "A list item cannot be preceded by itself";
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://www.essepuntato.it/2009/10/error/hasError> .

<urn:swrl#value> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-D6C6F522F62B39EE2729C09E92C84371 rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F606D3C0486AAFE9CCFA06143A17442A;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F0507A74DF24DDBBA4CFAF6EC3E21AFA a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-AB09CB30E01D451CD0719CAAC3F02FCF;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CDC97E6847249B7140009BC073F43CAC .

<http://purl.org/co/firstItemOf> a owl:ObjectProperty;
  rdfs:label "is first item of"@en;
  rdfs:comment "The relation between an object and a list in which the object is first item."@en;
  rdfs:subPropertyOf <http://purl.org/co/itemOf>;
  owl:inverseOf <http://purl.org/co/firstItem>;
  <http://purl.org/vocab/vann/example> """
    :author-1 a co:ListItem ;
        co:firstItemOf :authors .
    """;
  rdfs:isDefinedBy <http://purl.org/co/>;
  <http://www.w3.org/2003/06/sw-vocab-status/ns#term_status> <http://purl.org/linked-data/registry#statusStable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F96452B187B4F82C0B57A4A985B78304 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CDDC0EA45B5A28472ECCAAC8C14996E9;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FBEBE673D2F1B8EF9CD939351764A7C3 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C4C3A1D4F14C2B9668F6DFAB08B89C75 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F8A6CBC8ACC96D6A4DDBFAB11FA7A25A;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-631A5B9F9EA151E7E7D18D6EE2FF159F a owl:Class;
  owl:intersectionOf _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E7DD7C4537664949651B4E00EB858E49 .

<urn:swrl#r> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-39627A2D457151948F8AA51D465A7BF3 a rdf:List;
  rdf:first 1;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-8EB5C46088CB1536D71AC765B8F9A10F a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#x>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#x>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/precededBy> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-D827B630E0C081B548136A6F3BDDB72E a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-12C3CB18F726892C8BBC10B6C442E1D7;
  rdf:rest rdf:nil .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-387764CFBBEC832463FB5103C592D629 a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CF0E26D3502D9901715D4207091A7187;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-E10194ADAF16F94E9DC175F48F1E0C6A .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-D259B1B8AD5BCEC6FFF59A5640F37503 a owl:Restriction;
  owl:hasValue "1"^^xsd:positiveInteger;
  owl:onProperty <http://purl.org/co/index> .

<http://purl.org/dc/elements/1.1/date> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2F508B6140DCF5ABCD46336BF87E34F6 a <http://www.w3.org/2003/11/swrl#Imp>;
  <http://www.w3.org/2003/11/swrl#body> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C7EB573EA395E56E846CE2B5CB3DCE77;
  <http://www.w3.org/2003/11/swrl#head> _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C0A9668B27DFA633FA02DF5A53CD0A0E .

<urn:swrl#last> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A9AD7E0000681B91308F794136E5E1F0 a owl:Restriction;
  owl:maxCardinality "1"^^xsd:nonNegativeInteger;
  owl:onProperty <http://purl.org/co/lastItem> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-09C8B46C2440CFB0E22DBF1A9799CBBA rdf:first
    <http://purl.org/co/item>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-2997177C617B2D4BE4F4CF34C3ECAF4B .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-DD3EAA90F10DBF6DCE365B9AA1F6CAA3 a <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#list>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#r>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/size> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-35CCE8355F0C6A4C0C70477FA670228D rdf:first
    <http://purl.org/co/List>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-DE189C1E074D8D3848977222C7BD865A .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-7C5CFFB48726ECC6B525C38A2A88769B rdf:first
    <http://purl.org/co/Bag>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-32E40DE5FEC624F0A2C4498413433099 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-56F3602FC00214D2C29039FDD9BAEC5A rdf:first
    <http://purl.org/co/item>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-1923EA5B200CC0CDB259B0F002E0F058 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6E58F44C50E235CB761B0D752068C524 rdf:first
    <http://purl.org/co/ListItem>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-D6C6F522F62B39EE2729C09E92C84371 .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-6C01F90CE6B9300EA13BF357D00FAF55 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-47A2B25D5E24B63C8B698004361DA0A4;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-9EBDD0A2D9208BB22CDAE8E352432CED .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-FBEBE673D2F1B8EF9CD939351764A7C3 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-886570297553720699846680D264E856;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F0507A74DF24DDBBA4CFAF6EC3E21AFA .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-C7EB573EA395E56E846CE2B5CB3DCE77 a <http://www.w3.org/2003/11/swrl#AtomList>;
  rdf:first _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-160606A77AA0EF0C73E3F7FF4266C582;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F96452B187B4F82C0B57A4A985B78304 .

<urn:swrl#i> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-582497683D23452CA1AC76AD3B90ABE0 a owl:Restriction;
  owl:onProperty <http://purl.org/co/firstItem>;
  owl:someValuesFrom <http://purl.org/co/Item> .

<http://purl.org/dc/elements/1.1/creator> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-55199DA6A7100E6FA61B77FF271F92A0 a owl:Class;
  owl:complementOf <http://purl.org/co/Item> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-F352D6A3B78183CA56382F9CFF77AB63 owl:inverseOf
    <http://purl.org/co/item> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-A43860B8890A48249BE1A0780B16CAB1 a owl:Restriction;
  owl:cardinality "1"^^xsd:nonNegativeInteger;
  owl:onProperty <http://purl.org/co/size> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CA950F8E2D390B8EB8015125DD4EB58D rdf:first
    _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-99D10F43CAF594E8A0755AD04E92199D;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-AE8A12578F5B4136C368F872AABCB0EA .

<urn:swrl#current> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CDDC0EA45B5A28472ECCAAC8C14996E9 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#li2>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/itemOf> .

<urn:swrl#next> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-59B2046958D94B815880B3A28DACF548 rdf:first
    <http://purl.org/co/ListItem>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-CA950F8E2D390B8EB8015125DD4EB58D .

<http://purl.org/dc/elements/1.1/description> a owl:AnnotationProperty .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-B1637248847EEDA9EC63591E08A1B50B a rdf:List;
  rdf:first <urn:swrl#nextR>;
  rdf:rest _:genid-32bcfa2bb3d54030a1e0e8b5464777361498-BE16AA53582A29BEB751984C50ECC181 .

owl:Thing a owl:Class .

<http://purl.org/dc/elements/1.1/contributor> a owl:AnnotationProperty .

<urn:swrl#r1> a <http://www.w3.org/2003/11/swrl#Variable> .

_:genid-32bcfa2bb3d54030a1e0e8b5464777361498-7E6B09CF2EEA1B7F92916DB1B35E2182 a <http://www.w3.org/2003/11/swrl#IndividualPropertyAtom>;
  <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl#l>;
  <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl#li>;
  <http://www.w3.org/2003/11/swrl#propertyPredicate> <http://purl.org/co/firstItem> .

<urn:swrl#list> a <http://www.w3.org/2003/11/swrl#Variable> .

<urn:swrl#li2> a <http://www.w3.org/2003/11/swrl#Variable> .

<urn:swrl#l> a <http://www.w3.org/2003/11/swrl#Variable> .