@prefix tutorial: <http://jena.hpl.hp.com/2005/09/tutorial#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
(?x, tutorial:units, ?list) -> listMapAsSubject(?list, tutorial:inTrail, ?x) .
(?x, skos:broader, ?y) -> (?y, skos:narrower, ?x) .