GE> Any kind of programming languaGE that specifies output in terms of some property and some arguments. For example, if Tom has two brothers, Dick and Harry, a relational languaGE will respond to the query "Who is Tom' s brother?" with either Dick or Harry. Notice that unlike {functional languaGEs}, relational languaGEs do not require a unique output for each predicate/argument pair. Prolog is the best known relational languaGE. (2004-05-17)