# Domain and range

(Redirected from Domain)

The **domain** of a function is the set of arguments for which it is defined. Its **range** is the set of values it could return. Thanks to the unification of function application, list indexing, and dictionary lookup, the concepts of domain and range extend to any k object.

The domain of a list is `!#x`

and its range is the list itself. This is valid for tables too.

The domain of a dictionary is its keys `!x`

and the range is its values `. x`

.