I am saying it is impossible to account for all the control variables in this case, which is required for the experiment to work. — Chany

I'm saying I can make a random choice. I'll flip a coin and choose. That removes the difficulty of making things equal in all respects.

The idea that choices have to be rational to be choices is bizarre. They don't have to be rational. The ass would go to one pile or the other.

This doesn't mean that there are not important issues similar to this in computer programming, but there are ways to avoid a program getting stuck between two options.

You cannot solve it, but nature might solve it through chaos - meaning that eventually one stack of grass (I've heard the donkey and two carrots) will drift closer, thereby stimulating a decision (one way or the other, for the ass may prefer the further stack of grass on pure principle).