Question 1
An Uniform Resource Identifier (URI) defines a simple extensible schema for the unique identification of an abstract or physical resource. A URI can be further classified as a locator, a name, or both.
The term "Uniform Resource Locator" (URL) refers to the subset of URIs that, in addition to identifying a resource, locating the resource by describing its primary access mechanism. URIs can be classified as locators (URLs), or as names (URNs), or as both
Question 2
You were asked for implicit and explicit facts of the RDF graph. An explicit fact is information you can read directly from the graph. The fact that dbp:Sesame_Street is of type ex:TV_series can be seen directly in the graph
Ernie is of type ex:Singer because he is used as subject with the property ex:artist and this property has the rdf:domain ex:Singer.
Ernie is also of type ex:FictionalCharacters because he is directly of type ex:SesameStreetCharacters and this class is a subclass of ex:FictionalCharacters. Therefore every resource of type ex:SesameStreetCharacters is also of type ex:FictionalCharacters.
ex:Singer is a class and cannot be of type ex:Person but a subclass of it.
Ernie cannot be of type ex:bestFriend as ex:bestFriend is a property and not a class.
Not all instances of the class ex:Singer must be an ex:artist of a ex:MusicalWork. But, if the property ex:artist is used, it should connect a ex:Singer to a ex:MusicalWork.
Question 3
ex:Report1 a ex:publication .
This RDF statement can be inferred from the RDF statements
"ex:Report1 a ex:article ." and "ex:article rdfs:subClassOf ex:publication ."
ex:Report1 ex:creator ex:Tom .
This RDF statement t can be inferred from the RDF statements
"ex:author rdfs:subPropertyOf ex:creator." and "ex:Report1 ex:author ex:Tom ."
ex:Report2 a ex:publication .
This RDF statement can be inferred from the RDF statements
"ex:publishes rdfs:range ex:publication ." and "ex:FedEXpress ex:publishes ex:Report2 ."
ex:Tom ex:creator ex:Report1 .
This RDF statement cannot be inferred from the RDF statements
"ex:author rdfs:subPropertyOf ex:creator." and "ex:Tom ex:author ex:Report1." of the given graph. It should be "ex:Tom ex:creator ex:Report1 ."
ex:publication a ex:Report1 .
This RDF statement cannot be inferred from the RDF statements
"ex:Tom ex:author ex:report1." and "ex:publishes rdfs:range ex:publication ." of the given graph. It should be "ex:Report1 rdf:type ex:publication"
Question 4
The rdf:Seq element is intended to describe an ordered list of values. For instance, in alphabetical order.
The rdf:Seq element may contain duplicate values.
As rdf:seq is sub class of RDFS containers. rdf:Seq containers can be extended by adding new entries
rdf:first and rdf:rest are used to change the order of lists
Question 5
Datatype and Language can be assigned to a literal but we can not assign property restriction or URL identifying this literal
Question 6
The given graph is an RDF reified statement. Triples can not be deduced from RDF reified statements.
Question 7
ex:b rdf:type ex:c
This RDF statement can be inferred from the RDF statements
"ex:b rdf:type ex:a ." and "ex:a rdfs:subClassOf ex:c ." of the given graph
ex:c rdf:type ex:a
This RDF statement cannot be inferred as it contradicts the RDF statements
"ex:a rdfs:subClassOf ex:c ." and "ex:b rdf:type ex:a ." of the given graph
ex:a rdf:type ex:c
This RDF statement can be inferred from the RDF statements
"ex:a rdfs:subClassOf ex:c ." and "ex:a rdf:type ex:a" of the given graph
ex:b rdfs:subClassOf ex:c
This RDF statement can be inferred from the RDF statements
"ex:a rdfs:subClassOf ex:c ." and "ex:b rdfs:subClassOf ex:a." of the given graph
ex:a rdf:type ex:a
This RDF statement can be inferred from the RDF statements
"ex:a ex:b ex:c ." and "ex:b rdfs:domain ex:a" . of the given graph