ceil function:

• Can also be called as ceiling

If the argument is numeric, return it's ceiling.

Examples:

• running: (ceil 10.3) will give: 11

• running: (ceil -10.3) will give: -10

• running: (ceil -10) will give: -10

• running: (ceil -10.5) will give: -10

• running: (ceil 10.99) will give: 11

• running: (ceil [0]) will return nothing