An infinite group of mathematicians walk into a bar. One says to the bartender, "I'll have a pint please." The second says, "Half a pint, please." The third say

An infinite group of mathematicians walk into a bar. One says to the bartender, "I'll have a pint please." The second says, "Half a pint, please." The third says, "Quarter of a pint, please." Just as the fourth is about to open his mouth, the bartender says "I see what's happening" and pours 2 pints.