The program module in this subdirectory is a crude implementation ofCPLEX-like interface to GLPK API. It consists of two files: cplex.c andcplex.h.NOTE that this module is NOT a clean room implementation of the CPLEXcallable library. It only implements a CPLEX-like interface to the GLPKAPI routines, and its main purpose is to provide possibility to buildand run applications which normally use the CPLEX callable library.This module approximately corresponds to CPLEX 9.0.Currently this module can be used as a linear programming solver forConcorde, the state-of-the-art computer code for solving the symmetrictraveling salesman problem (TSP) developed by David Applegate, RobertBixby, Vasek Chvatal, and William Cook. For details about Concorde seeits web page at http://www.tsp.gatech.edu/concorde.html.To build Concorde along with GLPK you need to do the following:1. Configure, build, and install GLPK.2. Download the Concorde tarball co031219.tgz (version Dec 19, 2003),   unpack and unarchive it.3. Copy files cplex.h and cplex.c to subdirectory concorde/LP/.4. Create file named lpglpk.c in subdirectory concorde/LP/. This file   must contain the following two lines:      #include "cplex.c"      #include "lpcplex8.c"5. Configure Concorde in usual way (./configure) and then build it with   the following command:      make CPPFLAGS=-I. LPSOLVER_INTERFACE=lpglpk.c LPSOLVER_LIB=-lglpk   The Concorde executable can be found in subdirectory concorde/TSP/.Please note that currently this GLPK interface module does not supportsome important features (namely, CPXgetijdiv, CPXmdleave, CPXpivotin,CPXpivotout, and CPXstrongbranch), so large (more than 1000 nodes) TSPinstances cannot be solved in a reasonable time, and some instances maycause abnormal termination of Concorde (if CPXgetijdiv is called).