Release Message:  In any pub there is a customer who, if they drink, everybody in the pub drinks. Authored by Raymond Smullyan.

Description:  The drinker paradox (also known as drinker's principle, drinkers' principle or (the) drinking principle) is a theorem of classical predicate logic, usually stated in natural language as: There is someone in the pub such that, if he is drinking, everyone in the pub is drinking. The actual theorem is where D is an arbitrary predicate. The paradox was popularized by the mathematical logician Raymond Smullyan, who called it the "drinking principle" in his 1978 book What Is the Name of this Book?