diff -r 0f695eac7e07 -r e99a7fb6bff5 demo/mip_demo.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demo/mip_demo.cc	Mon Mar 01 02:26:24 2010 +0100
@@ -0,0 +1,72 @@
+/* -*- mode: C++; indent-tabs-mode: nil; -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library.
+ *
+ * Copyright (C) 2003-2010
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+///\file
+///\brief Demo program for the MIP solver interface.
+///
+/// This demo program shows how the LEMON MIP solver interface can be used.
+/// A simple mixed integer programming (MIP) problem is formulated and solved
+/// using the default MIP solver (e.g. GLPK).
+///
+/// \include mip_demo.cc
+
+#include <iostream>
+#include <lemon/lp.h>
+
+using namespace lemon;
+
+int main()
+{
+  // Create an instance of the default MIP solver class
+  // (it will represent an "empty" problem at first)
+  Mip mip;
+
+  // Add two columns (variables) to the problem
+  Mip::Col x1 = mip.addCol();
+  Mip::Col x2 = mip.addCol();
+
+  // Add rows (constraints) to the problem
+  mip.addRow(x1 - 5 <= x2);
+  mip.addRow(0 <= 2 * x1 + x2 <= 25);
+  
+  // Set lower and upper bounds for the columns (variables)
+  mip.colLowerBound(x1, 0);
+  mip.colUpperBound(x2, 10);
+  
+  // Set the type of the columns
+  mip.colType(x1, Mip::INTEGER);
+  mip.colType(x2, Mip::REAL);
+  
+  // Specify the objective function
+  mip.max();
+  mip.obj(5 * x1 + 3 * x2);
+  
+  // Solve the problem using the underlying MIP solver
+  mip.solve();
+
+  // Print the results
+  if (mip.type() == Mip::OPTIMAL) {
+    std::cout << "Objective function value: " << mip.solValue() << std::endl;
+    std::cout << "x1 = " << mip.sol(x1) << std::endl;
+    std::cout << "x2 = " << mip.sol(x2) << std::endl;
+  } else {
+    std::cout << "Optimal solution not found." << std::endl;
+  }
+
+  return 0;
+}