[Alexander] Grothendieck almost never worked with specific examples. It has been said that once, when he was asked to use a prime number to demonstrate something on the blackboard, he said, “You mean an actual number? OK, take fifty-seven.” Fifty-seven is not a prime number—it’s nineteen times three—and it is now known as Grothendieck’s prime.

Rivka Galchen, “The Mysterious Disappearance of a Revolutionary Mathematician”

[I]n 1954, [Yoko Ono] published her first book, “Grapefruit,” a collection of event scores and instruction pieces[.] […] These are like Brecht’s “Word Event,” but with a big difference. “Word Event” was intended to be performed, and artists found various ingenious ways to enact the instruction “Exit”. Ono’s pieces cannot be performed. They are instructions for imaginary acts.

Louis Menand, “Yoko Ono’s Art of Defiance”