I cannot use sh:lessThan with xsd:positiveInteger

Question

I have the following small ontology, with two classes ("DataSubject" and "Minor"), one property has-age from DataSubject(s) to xsd:positiveInteger, and one individual ("John", who is a DataSubject and has-age equal to 20).

ontology:DataSubject
  rdf:type owl:Class ;
  rdfs:subClassOf owl:Thing ;
  owl:disjointWith ontology:Minor ;
  owl:disjointWith owl:NamedIndividual ;
.
ontology:John
  rdf:type ontology:DataSubject ;
  ontology:has-age "20"^^xsd:positiveInteger ;
.
ontology:Minor
  rdf:type owl:Class ;
  rdfs:subClassOf owl:Thing ;
  owl:disjointWith ontology:DataSubject ;
  owl:disjointWith owl:NamedIndividual ;
.
ontology:has-age
  rdf:type owl:DatatypeProperty ;
  rdfs:domain ontology:DataSubject ;
  rdfs:range xsd:positiveInteger ;
.

The following SHACL rule SHOULD mark as Minor all DataSubject(s) whose age is lower than 16.

rules:WhenDataSubjectIsMinor
  rdf:type sh:NodeShape ;
  sh:rule [
      rdf:type sh:TripleRule ;
      #IF: "the age of the Data Subject is lower than 16"
      sh:condition [
        sh:property [
          sh:path ontology:has-age;
          sh:lessThan "16"^^xsd:positiveInteger ;
        ] ;
      ] ;
      #THEN: "the Data Subject is marked as type Minor"
      sh:subject sh:this ;
      sh:predicate rdf:type;
      sh:object ontology:Minor ;
  ] ;
  sh:targetClass ontology:DataSubject ;
.

However, the following Java code infers John as Minor... but John is not, he is 20 years old! Of course the rule is not correct, specifically the instruction "sh:lessThan "16"^^xsd:positiveInteger ;".

How can I compare datatype properties with given constants?

Thanks in advance!

Livio

    public static void main(String[] args) throws Exception
    {
            //Load the ontology
        Model ontology = JenaUtil.createMemoryModel();
        FileInputStream fisOntology = new FileInputStream("./ontology.ttl");
        ontology.read(fisOntology, "urn:dummy", FileUtils.langTurtle);
        
            //Load the rules
        Model rules = JenaUtil.createMemoryModel();
        FileInputStream fisRules = new FileInputStream("./rules.ttl");
        rules.read(fisRules, "urn:dummy", FileUtils.langTurtle);
        
            //Executing the rule and print
        Model inferredTriples = RuleUtil.executeRules(ontology, rules, null, null);
        System.out.println(ModelPrinter.get().print(inferredTriples));
    }

Answer 1

sh:lessThan is used to establish relationships between two properties, e.g. date of birth sh:lessThan date of marriage. What you need is sh:maxExclusive.

See the SHACL spec for details, e.g. https://www.w3.org/TR/shacl/#LessThanConstraintComponent