@prefix : <http://example.org/socrates#>.
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.

:Socrates a :Human.
:Socrates a :Mortal.
{
    :Socrates a ?U_0.
} => {
    :Socrates a ?U_0.
}.

:Human rdfs:subClassOf :Mortal.
{
    ?U_1 rdfs:subClassOf ?U_2.
    ?U_3 a ?U_1.
} => {
    ?U_3 a ?U_2.
}.

