Availability::- use_module(library(semweb/rdf_db)).
[nondet]rdf_reachable(?Subject,
+Predicate, ?Object, +MaxD, -D)Same as rdf_reachable/3, but
in addition, MaxD limits the number of edges expanded and D
is unified with the `distance' between
Subject and Object. Distance 0 means Subject
and Object are the same resource. MaxD can be the
constant infinite to impose no distance-limit.
