Relational TrafoLa-H is a language where each expression may have several or even infinitely many values, and each `function' may produce many results. Its functional predecessor was developed to ease the specification of complex tree transformations starting from a usual functional language similar to HOPE or ML. The non-determinism resulting from its complex patterns was the reason to turn the functional language into a relational one.
Reinhold Heckmann / heckmann@absint.com