Definition:Ceiling Function

Definition
Let $x$ be a real number.

Informally, the ceiling function of $x$ is the smallest integer greater than or equal to $x$.

Also denoted as
Some sources use $\set x$, but this has too many other uses for it to be acceptable on.

Also see

 * Equivalence of Definitions of Ceiling Function
 * Definition:Floor Function
 * Definition:Fractional Part
 * Properties of Ceiling Function