Protégé：DL Query 和 SPARQL Query 之间的不同结果

Question

Here is a small ontology called wildlife.owl , created by Protégé, in which I have classes animal , carnivore , herbivore , lion , giraffe , and individuals Léo (a lion ), Gigi (a giraffe ) and Giginou (also a giraffe ). In the ontology I only declare that lion ⊏ carnivore ⊏ animal .

When I ask for the instances of animal in the DL Query tab of Protégé, I get, among others, Léo (which is a lion , hence a carnivore , hence an animal ).

But when I write the following SPARQ Query:

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 xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX me: <file:wildlife.owl#>
SELECT ?b
    WHERE { ?b rdf:type me:animal }

I don't get any instance. Same result when I replace me:animal by me:carnivore . Only when I replace it by me:lion I get the desired result Léo .

Why is DL Query doing the inference (allowing me to obtain Léo as instance of the animal class) and not SPARQL Query?

What can I do to get the same result in SPARQL Query?

---

Thanks to the answer by @UninformedUser I now know that I must use the Snap SPARQL Query and not the SPARQL Query.

My next question concerns Python: when I send the SPARQL Query using Owlready2 and RDFlib, again I get no result:

 from owlready2 import * from rdflib import * onto = get_ontology("wildlife.owl").load() sync_reasoner([onto]) graph = default_world.as_rdflib_graph() print(list(graph.query_owlready(""" PREFIX rdf-syntax: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX me: <file:wildlife.owl#> SELECT ?b WHERE { ?b rdf-syntax:type me:animal . }""")))

How can I get this query use OWL Reasoner?

Answer 1

When calling the reasoner, Owlready does not retain trivia inferences, such as is-a transitivity (eg the fact that lion is an animal).

For trivial inferences, you should rather use SPARQL, as in the example below. The ?any_animal variable contains all animal subclasses (including animal itself), thank to the SubclassOf* SPARQL syntax (the * indicates transitivity). Then, we take any instance of ?any_animal class.

    from owlready2 import *
    from rdflib import *

    onto = get_ontology("http://test.org/wildlife.owl")

    with onto:
        class animal(Thing): pass
        class carnivore(animal): pass
        class lion(carnivore): pass

        lion()

    default_world.graph.dump()

    graph = default_world.as_rdflib_graph()

    print(list(graph.query_owlready("""
    PREFIX rdf-syntax: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
    PREFIX me: <http://test.org/wildlife.owl#>
    SELECT ?b WHERE {
    ?any_animal <http://www.w3.org/2000/01/rdf-schema#subClassOf>* me:animal .
    ?b rdf-syntax:type ?any_animal .
    }""")))