Question: "Which is {name after} of {Sierpinski triangle}, whose {ethnicity} is {Poles} ?"
Paraphrase: "Which is {name after} of {Sierpinski triangle}, whose {ethnicity} is {Poles} ?"
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q663365 wdt:P138 ?answer . ?answer wdt:P172 wd:Q1026}
Answer: Wacław Sierpiński