This month we ask our readers to solve a well-known logic puzzle from Singapore “Cheryl’s Birthday“. The objective is to determine the birthday of a girl named Cheryl using a handful of clues given to her friends Albert and Bernard.

Last month Peter Norvig asked nine LLM chatbots to solve this problem and concluded: “Most of them were familiar with the problem and correctly recalled the answer: July 16. But none of them were able to write a program that finds the solution. They all failed to distinguish the different knowledge states of the different characters over time. At least with respect to this problem, they had no theory of mind.” Can you do better? Link