firstname.lastname@example.org wrote: > On Saturday, July 27, 2013 12:36:32 AM UTC+1, Peter Percival wrote: >> Paul wrote: >> >>> Let n be a fixed integer > 1. n logicians walk into a bar. The >> >>> barwoman says "Do all of you want a beer?" The first logician says >> >>> "I don't know." The second logician says "I don't know." ... The >> >>> n-1st logician says "I don't know." The nth logician says "Yes >> >>> please." >> >> >> >> That doesn't answer the question correctly. > ... > > Please could you state your objection? Everyone is narrowly focusing on the yes/no question: "Do all of the n logicians want a beer?" Everyone saying "I don't know" clearly wants a beer because, if they didn't want a beer, they would know that not everyone wants a beer and would answer "no" instead of "I don't know." > The nth logician follows the above reasoning and also wants to drink beer, so says "yes". >
It isn't clear to me that "I don't know" actually means "I do, but I cannot peak for my fellows." It may be that "I don't know" is short for "I don't know, I'm still thinking about it." Or it may be that "I don't know" is short for "I do but Robinson is in our party and he always takes 10 minutes to make his mind up."
-- Nam Nguyen in sci.logic in the thread 'Q on incompleteness proof' on 16/07/2013 at 02:16: "there can be such a group where informally it's impossible to know the truth value of the abelian expression Axy[x + y = y + x]".