ASK
{
  BIND (BNODE ("a") AS ?a) .
  BIND (BNODE ("b") AS ?b) .
  # Check prefix
  FILTER (SUBSTR(STR(?a), 0, 11) = 'urn:bnode:') .
  FILTER (SUBSTR(STR(?a), 0, 11) = SUBSTR(STR(?b), 0, 11)) .
  # Check UUIDv4 version char, this is always 4
  FILTER (SUBSTR(STR(?a), 25, 1) = '4') .
  FILTER (SUBSTR(STR(?a), 25, 1) = SUBSTR(STR(?b), 25, 1)) .
}
