June 16 (UPI) -- A Pennsylvania math professor shared a photo of an unusual sign at her local deli: "Please refrain from discussing mathematics while waiting in line."
Anna Haensch, professor of mathematics at Duquesne University, tweeted a photo she snapped while waiting near checkout at an unidentified deli in Pittsburgh.
"Please refrain from discussing mathematics while waiting in line," the sign reads.
"At the local deli. What could have happened to make them put up that sign??" Haensch tweeted.
Twitter users were quick to step in with their pun-filled theories:
"Perhaps they thought those conversations were getting too irrational?" @ScottUWEC quipped.
"Some of them got downright complex," @tadmanter added.
"You've gotta ask!!! I'm imagining fisticuffs over fibonaci or something like that," @maiasz theorized.
Twitter user @patrickray1969 had a complaint about the accuracy of the sign: "Technically it's a line SEGMENT."