Publication in EndNote Format

%0 Report
%@ 309
%A Warren, David H. D.
%T An Abstract Prolog Instruction Set
%C 333 Ravenswood Ave., Menlo Park, CA 94025
%I AI Center, SRI International
%D 1983
%K Prolog
%X This report describes an abstract Prolog instruction set suitable for software,
   firmware, or hardware implementation. The instruction set is abstract in that
   certain details of its encoding and implementation are left open, so that it may
   be realized in a number of different forms. The forms that are contemplated are:
   
 em Translation into a compact bytecode, with emulators written in C (for
   maximum portability), Progol (a macrolanguage generating machine code, for efficient
   software implementations as an alternative to direct compilation on machines such
   as the VAX), and VAX-730 microcode. em Compilation into the standard instructions
   of machines such as the VAX or DECsystem-10/20. em Hardware (or firmware) emulation
   of the instruction set on a specially designed Prolog processor. 
 The abstract
   machine described herein (``new Prolog Engine’’) is a major revision
   of the ``old Prolog Engine’’ described in a previous document. The
   new model overcomes certain difficulties in the old model, which are discussed
   in a later section. The new model can be considered to be a modification of the
   old model, where the stack contains compiler-defined goals called environments
   instead of user-defined goals. The environments correspond to some number of goals
   forming the tail of a clause. The old model was developed having primarily in
   mind a VAX-730 microcode implementation. The new model has, in addition, been
   influenced by hardware implementation considerations, but should remain equally
   amenable to software or firmware implementation on machines such as the VAX.
%U http://www.ai.sri.com/pubs/files/641.pdf