G-LOG is a PROLOG semi-compiler written in the C
programming language. G-LOG was designed to be a
transportable, easily extensible non-procedural language
which provides easy access to routines written in other
programming languages. A primary use of G-LOG will be
for the construction of a non-procedural executive for
an expert system which calls existing routines to
execute procedural functions. This versatility should
enable industry investments in complex programs to be
updated into a customized expert system. The history
and philosophy of PROLOG is sketched first, then the
syntax required by G-LOG is presented. The
implementation of G-LOG is discussed in detail. Novel
aspects of G-LOG include semi-compilation of variables
and user-written system primitives. Guidelines for the
application programmer are given.