Question: What was the occupation of both Lev Pontryagin and Vladimir Drinfeld?
Sentence (from "Vladimir Drinfeld"): Vladimir Gershonovich Drinfeld (Russian: Влади́мир Гершо́нович Дри́нфельд ; born February 14, 1954), surname also romanized as Drinfel'd, is a Ukrainian mathematician currently working at the University of Chicago.
Relevant evidence: Yes