Thought this was a fascinating example of the perils of naive floating-point summation. I knew that one had to be careful with floating-point math, but I had no idea that this kind of thing was possible:<p>> The sumsto function always returns the same 2046 floating-point numbers but returns them in a different order based on x: for any 64-bit float value of x from 0 up to (but not including) 2^970, the naive left-to-right sum of the vector returned by sumsto(x) is precisely x