> [Mercury] feels like lego where prolog is duplo. Except for things like the system described in the featured article, where the unique strength of Prolog is

> [Mercury] feels like lego where prolog is duplo. Except for things like the system described in the featured article, where the unique strength of Prolog is the ability to pass around partially instantiated data structures and use full unification. Last time I checked, Mercury still insisted that terms be ground (or completely free variables), which means that for this kind of problem you don't gain much from its flavor of logic programming :-(