Prolog is a programming language, but a rather unusual one. ``Prolog is short
for ``Programming with Logic, and the link with logic gives Prolog its
special character. At the heart of Prolog lies a surprising idea: dont tell
the computer what to do. Instead, describe situations of interest, and compute
by asking questions. Prolog will logically deduce new facts about the
situations and give its deductions back to us as answers.

Why learn Prolog? For a start, its ``say what the problem is, rather than how
to solve it stance, means that it is a very high level language, good for
knowledge...