In the Futurama episode “Put Your Head on My Shoulders,” a short-lived love blossoms between Amy Wong and the Planet Express crew’s low-functioning delivery boy, Fry. They start doing “it” anywhere they can find a little privacy, including the supply closet. At one point, after Fry’s head is surgically implanted next to Amy’s, they revisit the supply closet, and on the shelves behind them, below a can of “Emergency Beans” and “Condensed Milt,” are two boxes. One is labeled “P,” another labeled “NP.”

The boxes reference a famous theoretical computer science problem known as “P vs. NP.” To give you an idea of how important this problem is, the Clay Mathematics Institute has offered $1 million to anyone who can definitively prove that P either does, or doesn’t, equal NP, according to MIT News. “P” stands for problems solved in polynomial time. Basically, they’re relatively quick and easy. Everything else is classified as “NP.” The equation “P = NP” says that a computer can solve these complicated NP problems with as few moves as it uses to solve the P problems. So, in its essence, “P = NP” means computer algorithms could find a way to simplify extremely complicated problems that require a lot of individual executions, down to ones that only require a handful of steps. Of course, the majority of computer scientists don’t think that this can be done, but none have proven it can’t.

The P vs. NP question has led to several important discoveries in the computer science world, that most laypeople wouldn’t understand. Ken Keeler, though, who wrote the episode and holds a PhD in applied mathematics from Harvard (and has admitted to injecting math humor into other parts of the show) would most definitely get it.