result_rdf(iri('https://example.org/sensor1'), iri('https://example.org/reportedBy'), iri('https://example.org/station7'), default_graph).

clause(1,
       rdf(iri('https://example.org/sensorGraph'), iri('https://example.org/reportedBy'), iri('https://example.org/station7'), default_graph),
       true).
clause(2,
       rdf(iri('https://example.org/sensor1'), iri('https://example.org/temperature'), literal('21.5', datatype('http://www.w3.org/2001/XMLSchema#string')), iri('https://example.org/sensorGraph')),
       true).
clause(3,
       result_rdf(var('S'), iri('https://example.org/reportedBy'), var('Station'), default_graph),
       (rdf(iri('https://example.org/sensorGraph'), iri('https://example.org/reportedBy'), var('Station'), default_graph),
        rdf(var('S'), iri('https://example.org/temperature'), anonymous(1), iri('https://example.org/sensorGraph')))).

step(result_rdf(iri('https://example.org/sensor1'), iri('https://example.org/reportedBy'), iri('https://example.org/station7'), default_graph),
     rule(3),
     ['S' = iri('https://example.org/sensor1'), 'Station' = iri('https://example.org/station7')],
     [rdf(iri('https://example.org/sensorGraph'), iri('https://example.org/reportedBy'), iri('https://example.org/station7'), default_graph),
      rdf(iri('https://example.org/sensor1'), iri('https://example.org/temperature'), literal('21.5', datatype('http://www.w3.org/2001/XMLSchema#string')), iri('https://example.org/sensorGraph'))]).
step(rdf(iri('https://example.org/sensorGraph'), iri('https://example.org/reportedBy'), iri('https://example.org/station7'), default_graph),
     fact(1),
     [],
     []).
step(rdf(iri('https://example.org/sensor1'), iri('https://example.org/temperature'), literal('21.5', datatype('http://www.w3.org/2001/XMLSchema#string')), iri('https://example.org/sensorGraph')),
     fact(2),
     [],
     []).