PREFIX era: SELECT DISTINCT * { GRAPH { ?sol a era:SectionOfLine. ?sol era:opStart ?op_start. ?op_start era:opName ?op_startName . ?sol era:opEnd ?op_end. ?op_end era:opName ?op_endName . FILTER (regex(?op_startName,"Dendermonde")) . FILTER (regex(?op_endName,"Zele")). ?sol era:track ?track . ?track era:wheelSetGauge ?wheelSetGauge . } }