Question: Frederick Valentine Atkinson, was a British mathematician, formerly of the University of Toronto, a public research university in Toronto, Ontario, in which country?
Sentence (from "Atkinson–Mingarelli theorem"): In applied mathematics, the Atkinson–Mingarelli theorem, named after Frederick Valentine Atkinson and A. B. Mingarelli, concerns eigenvalues of certain Sturm–Liouville differential operators.
Relevant evidence: No