diff -r d59bea55db9b -r c445c931472f examples/cpp.mod
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/cpp.mod	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,67 @@
+/* CPP, Critical Path Problem */
+
+/* Written in GNU MathProg by Andrew Makhorin <mao@gnu.org> */
+
+/* Note: Reduced costs of auxiliary variables phi[j,k] (see below)
+         can be only zero or one. The critical path is defined by the
+         constraints, whose reduced cost is one. */
+
+set J;
+/* set of jobs (activities) */
+
+set P{j in J}, in J, default {};
+/* P[j] is a subset of jobs that immediately precede job j */
+
+param t{j in J}, >= 0;
+/* duration required to perform job j */
+
+var x{j in J}, >= 0;
+/* starting time of job j */
+
+s.t. phi{j in J, k in P[j]}: x[j] >= x[k] + t[k];
+/* job j can start only after all immediately preceding jobs have been
+   completely performed */
+
+var z;
+/* project makespan */
+
+s.t. fin{j in J}: z >= x[j] + t[j];
+/* which is the maximum of the completion times of all the jobs */
+
+minimize obj: z;
+/* the objective is make z as small as possible */
+
+data;
+
+/* The optimal solution is 46 */
+
+param : J :  t :=
+        A    3    /* Excavate */
+        B    4    /* Lay foundation */
+        C    3    /* Rough plumbing */
+        D   10    /* Frame */
+        E    8    /* Finish exterior */
+        F    4    /* Install HVAC */
+        G    6    /* Rough electric */
+        H    8    /* Sheet rock */
+        I    5    /* Install cabinets */
+        J    5    /* Paint */
+        K    4    /* Final plumbing */
+        L    2    /* Final electric */
+        M    4    /* Install flooring */
+;
+
+set P[B] := A;
+set P[C] := B;
+set P[D] := B;
+set P[E] := D;
+set P[F] := D;
+set P[G] := D;
+set P[H] := C E F G;
+set P[I] := H;
+set P[J] := H;
+set P[K] := I;
+set P[L] := J;
+set P[M] := K L;
+
+end;