Thanks, I hadn't heard of that one! Another very interesting language in the Prolog family is Mercury (http://www.mercurylang.org/ http://www.mercurylang.org/)

Thanks, I hadn't heard of that one! Another very interesting language in the Prolog family is Mercury (http://www.mercurylang.org/ http://www.mercurylang.org/), which has a more functional and static flavour than Prolog, and has a suite of compilers that can produce quite efficient code.