Utility class for triples.
Checks whether a triple is assertional.
Intuitively, an assertional triple denotes information about the ABox of the ontology, such as
instance class membership or instance equality/inequality (owl:sameAs/owl:differentFrom)
(we consider the oneOf construct as simple C(a) assertions).
the triple to check
Checks whether a triple is terminological.
A terminological triple denotes information about the TBox of the ontology (class and property axioms),
such as subclass relationships, class equivalence, property types, etc.
Returns the position of the node in the triple.
Returns the position of the node in the triple. If the node does not occur, -1 will be returned.