It provides interface for system dependent procedures.
In other words, there is interface declaration of a function and subroutines
whose feature is regarded as system dependent.
Implementation of these procedures are given in files with corresponding name
(i.e. that begins with sysdep-).
Note that a procedure with one name may have several implementations.
The sysdep has no dependence to other modules.
AbortProgram(str) subroutinecharacter(len = *).
AbortProgram terminates program.
It is a generic name of a subroutine.
In fact, the subroutine was given another name SysdepAbort,
in order to make it easier to find the source code.
Though many implementations are trying to set exit code
other than zero, that should not be relied upon.