Checking unexpected inferred facts

In this example we can check if unexpected inferred facts cannot be inferred from the ontology.

Consider this simple ontology (the same one used in Checking expected inferred facts):

@prefix example: <http://example.onto/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

example:Human rdfs:subClassOf example:Mortal .
example:Icaro a example:Human .

It says that Human is a sub class of Mortal, and that Icaro is a human. From this one can simply infer that Icaro is mortal.

Moreover, as the domain and range of the property rdfs:subClassOf is rdfs:Class and owl:Class is sub class of rdfs:Class, both Mortal and Human are instances of owl:Class.

We want to be sure that example:Icaro a example:Student cannot be inferred. We use the code below:

from diderot import DiderotTestCase, cannot_infer


class ExpectedFactsTestCase(DiderotTestCase):

    def test_check_unexpected_facts(self):
        UNEXPECTED_FACTS = "<http://example.onto/Icaro> a <http://example.onto/Student> ."
        ONTOLOGY_FILE = "example/db/check_expected_facts/ontology.n3"
        self.assert_that(cannot_infer(UNEXPECTED_FACTS).from_facts(ONTOLOGY_FILE))
EXPECTED_ANSWER = [(anyURI(), anyInt(), anyString())]
self.assert_that(can_answer(QUESTION).from_ontology(ONTOLOGY_FILE).with_answer(EXPECTED_ANSWER))

import sure

(5).should.be.an('int')

This is useful in a stage of ontology development that we have not added example:Student to the ontology yet but in the future it will exist, so this test will fail, or can be changed to use can_infer() instead of cannot_infer().

Now we want to see the test fail adding a fact we know it can be inferred, such as example:Icaro a example:Mortal ..

$ make test
======================================================================
FAIL: test_check_unexpected_facts_fail (test.test_unexpected_facts.ExpectedFactsTestCase)
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Traceback (most recent call last):
  File "/path/test_unexpected_facts.py", line 16, in test_check_unexpected_facts_fail
    self.assert_that(cannot_infer(UNEXPECTED_FACTS).from_facts(ONTOLOGY_FILE))
  File "/path/diderot/case.py", line 30, in assert_that
    raise AssertionError(assertion.assertion_error_message)
AssertionError: Could infer some unexpected facts:

  <http://example.onto/Icaro> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
     <http://example.onto/Mortal>.
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