The first mathematician orders a beer
The second orders half a beer
« I don't serve half-beers » the bartender replies
« Excuse me? » Asks mathematician #2
« What kind of bar serves half-beers? » The bartender remarks. « That's ridiculous. »
« Oh c'mon » says mathematician #1 « do you know how hard it is to collect an infinite number of us? Just play along »
« There are very strict laws on how I can serve drinks. I couldn't serve you half a вееr even if I wanted to. »
« But that's not a problem » mathematician #3 chimes in « at the end of the joke you serve us a whole number of beers. You see, when you take the sum of a continuously halving function- »
« I know how limits work » interjects the bartender
« Oh, alright then. I didn't want to assume a bartender would be familiar with such advanced mathematics »
« Are you kidding me? » The bartender replies, « you learn limits in like, 9th grade! What kind of mathematician thinks limits are advanced mathematics? »
« HE'S ON TO US » mathematician #1 screeches
Simultaneously, every mathematician opens their mouth and out pours a cloud of multicolored mosquitoes. Each mathematician is bellowing insects of a different shade.
The mosquitoes form into a singular, polychromatic swarm. « FOOLS » it booms in unison, « I WILL INFECT EVERY BEING ON THIS PATHETIC PLANET WITH MALARIA »
The bartender stands fearless against the technicolor hoard. « But wait » he inturrupts, thinking fast, « if you do that, politicians will use the catastrophe as an excuse to implement free healthcare. Think of how much that will hurt the taxpayers! »
The mosquitoes fall silent for a brief moment. « My God, you're right. We didn't think about the economy! Very well, we will not attack this dimension. FOR THE TAXPAYERS! » and with that, they vanish.
A nearby barfly stumbles over to the bartender. « How did you know that that would work? »
« It's simple really » the bartender says. « I saw that the vectors formed a gradient, and therefore must be conservative. »