Collection of miscellaneous Prolog code/extensions.

lang/prolog/code/ext/

   atn/       ATN: Prolog transition net interpreter.
   cugini/    CUGINI Extensions: NBS/ICST Prolog Utility 
              Library
   dlists/    DLISTS: Prolog doubly-linked list package.
   env/       O'Keefe's Environment Package for enhancing 
              Prolog portability
   fw_rules/  FW_Rules: Support for Forward Chaining Rules in 
              Prolog
   id/        Prolog Iterative Deepening Interpreter
   interval/  INTERVALS: Prolog sets-as-interval predicates
   jorge/     Prolog list-handling predicates.
   length/    Bounded-length version of the list-length 
              predicate
   trees/     Prolog 2-3 Trees Package
   vaucher/   Jean Vaucher's implementation of structures in 
              Prolog.