A Maple expression is with a unit if it is the function Units[Unit] applied to some arguments, a rational power of such an expression, or a product of such expressions, potentially also with another Maple expression.

The function call type(expr, with_unit) returns true if expr is of the form described above. Otherwise, false is returned.

In the remainder of this help page, we will refer to the product of the powers of the Units[Unit] function as the unit of the expression, and the product of the remaining factors (if any) as the multiplier. If there are no other factors, the multiplier is .

If an optional type typ is given and expr is of the form described above, it additionally checks that the multiplier is of the type typ. The function returns true if this additional condition is satisfied. Otherwise, false is returned.

If optional arguments coeff and unit are given and type(expr, with_unit(typ)) returns true, then the unit of expr is assigned to unit and the multiplier is assigned to coeff.