Whenever ALP needs to search for one of its own component files (such as the messages file), the value of the BaseEXE internal variable is translated to uppercase and is used to construct the name of an ALP specific environment variable having the form "<BaseEXE>_PATH." For example, if the value of BaseEXE is "alp," then an environment variable called ALP_PATH would be constructed and an attempt would be made to locate it in the environment. If found, its contents would be expected to contain a list of directories in a format identical to that of the standard PATH environment variable. ALP then searches this list of paths when attempting to locate the component file.