To fire up Prolog locally, you should contact your systems administrator. You should have either SICStus or SWI Prolog, or a Prolog compiler compatible with one of these. Once Prolog is fired up, you will see a prompt. The Prolog prompt should look like:
| ?-
It is important that Prolog be invoked from a directory for which the user has write permission. ALE, in the process of compiling user programs, writes a number of local files.