** Prolog** is based on ** F**irst ** O**rder ** P**redicate ** L**ogic
---sometimes abbreviated to FOPL.

First order * predicate logic* implies the existence of a set
of predicate symbols along with a set of connectives.

* First order* predicate logic implies that
there is no means provided
for ``talking about'' the predicates themselves.

** Prolog** is based on FOPL but uses a restricted version
of the * clausal form*.
Clausal form is a particular way of writing the propositions
of FOPL.
The restriction is known as * Horn clause form*.

** Prolog** is a so-called * logic programming* language.
Strictly, it is not the only one but most such languages are its descendents.

We will spend a little time outlining the basic ideas underlying
both propositional and predicate logic.
It is not the intention to use ** Prolog** as a vehicle to teach logic but
some appreciation of the issues is invaluable.

Mon May 24 20:14:48 BST 1999