Virtuoso supports "MINUS" SPARQL 1.1 feature. For example:


SQL> SPARQL
SELECT COUNT(*)
WHERE
  {
    { ?s ?p "Novosibirsk" } MINUS { ?s ?p "Новосибирск" } }

callret-0
INTEGER
 313
No. of rows in result: 1

This query is equivalent to the following query:

SQL> SPARQL
SELECT COUNT(*)
WHERE
  {
    ?s ?p "Novosibirsk"  FILTER NOT EXISTS { ?s ?p "Новосибирск" }
  }

callret-0
INTEGER
313
No. of rows in result: 1