Question: Did Juan Carlos Portillo González and Mieczysław Kościelniak share the same nationality?
Sentence (from "Mieczysław Kościelniak"): Mieczysław Kościelniak( 29 January 1912 in Kalisz – 5 March 1993 in Słupsk) was a Polish painter, graphic designer, and draftsman, brother of Władysław and Tadeusz Kościelniak.
Relevant evidence: Yes