[Math] How to represent the ceiling function using mathematical notation

Question

How to represent the ceiling function using mathematical notation?

I need an equation to input in a program because it doesn't except the ceiling function so it has to be some sort of mathematical equation. I also can't convert decimal numbers to integers within the string.

I know the floor function can be represented mathematically most simply as "x-x mod 1" or using an arctan equation but is there something similar to these mathematical formats for the ceiling function?

Thanks!!

Answer 1

Note that $\lceil x\rceil = -\lfloor -x\rfloor$.