Question: What are the conjecture which start with the letter problem
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q319141 . ?sbj rdfs:label ?sbj_label . FILTER(CONTAINS(lcase(?sbj_label), 'problem')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25