Magic for Filter Optimization in Dynamic Bottom-up Processing
  Off-line compilation of logic grammars using Magic allows an incorporation of filtering into the logic underlying the grammar. The explicit definite clause characterization of filtering resulting from Magic compilation allows processor independent and logically clean optimizations of dynamic bottom-up processing with respect to goal-directedness. Two filter optimizations based on the program transformation technique of Unfolding are discussed which are of practical and theoretical interest. 
Guido Minnen (SFB 340, Univ. of Tuebingen)