Probably the rules index was created. What the creation of the rules index does is to infer new triples. These new inferred triples are stored in a view under the mdsys schema. The viewname is RDFI_<rules_index_name>.
SQL> describe mdsys.RDFI_<rules_index_name>
will tell you whether this view exists. You can query the view, count the number of rows in the view etc.