# Abstract Data TypesAn Example Package Declaration

## CONSTANT re : INTEGER := 0;

## CONSTANT im : INTEGER := 1;

## TYPE complex IS ARRAY (NATURAL RANGE re TO im) OF REAL;

## FUNCTION "+" (a, b : complex) RETURN complex;

## FUNCTION "-" (a, b : complex) RETURN complex;

## FUNCTION "*" (a, b : complex) RETURN complex;

## FUNCTION "/" (a, b : complex) RETURN complex;

** Notes: **

This is a package declaration for a package that implements a complex number data type. Note that the data type is given as well as some standard operators on that type.