We do this with the set operation
applied on instance k:
{ Precondition: Let k
= n where n
is any Integer } k.set(i.add(j)) {
Postcondition: k
= i + j
}
Implementation of ADT: Step 3: add
(Cont.)
MODULAR
PROGRAMMING
int i, j, k; /* Define three integers */
i = 1; /* Assign 1 to integer i */
j = 2; /* Assign 2 to integer j */
k = i + j; /* Assign the sum of i and j to k */
Consider the ADT Integer. Outline the relationship
to the ADT Integer in the following
code:
The postcondition ensures
that i and j do not change their values. Please recall the
specification of add. It says that a new Integer is created the value
of which is the sum. Consequently, we must provide a mechanism to access this
new instance.