MORE INFORMATION on Domain.f
This example illustrates the reliability of P-testing. (Please refer to Combination.f)
If we assume that P is a set of programs which are either correct or contain domain errors, we may establish a relationship
between the paths in the incorrect programs P and in the corresponding correct programs P* so that:
for all paths in P.
The conditions for the reliability of P-testing for domain errors are simplified when a program's paths are 'distinct'.
A definition for distinction of paths in a program is defined by Howden thus:
Suppose P1 and P2 are two paths in a program with domain D. P1 and P2 are
distinct if P1(x) != P2(x) for all x in D. The paths in a program are distinct if any pair of paths in the program is distinct.
In this program, an incorrect transfer statement causes a domain error. The paths in the program are not distinct. P-testing is neither
reliable nor almost reliable for this example.