What is the {chemical element} with the {MIN(time-weighted average exposure limit)} whose {subclass of} is {group 13}  ?
Which {chemical component} has {MIN(time-weighted normal introduction restrain)} whose {subclass of} is {gather 13} ?
Which {chemical element} has {MIN(time-weighted average exposure limit)} whose {subclass of} is {group 13} ?
SELECT ?c WHERE { ?c rdf:type ontology:group_13 . . ?c rdf:type ontology:chemical_element . ?c property:time-weighted_average_exposure_limit ?r }
select ?ent where {
?ent <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q11344>.

?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2404>.
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj1.

?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P279> .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q189294> .

}
ORDER BY ASC(?obj1)
LIMIT 5
select ?ent where { ?ent wdt:P31 wd:Q11344 . ?ent wdt:P2404 ?obj . ?ent wdt:P279 wd:Q189294. } ORDER BY ASC(?obj)LIMIT 5 