HiLog

   A higher-order logic programming language.  An extension of
   normal logic programming where predicate symbols may be
   variable or structured.  This allows unification to be
   performed on the predicate symbols themselves in addition to
   their arguments.

   (ftp://sbcs.sunysb.edu/SB-hilog).

   ["HiLog as a Platform for Database Languages (Or Why Predicate
   Calculus is Not Enough)", W. Chen et al, Stony Brook, 2nd Intl
   Workshop on Database Prog Langs, Morgan Kaufmann, 1989].

   (1994-12-07)