diff -r eb6c34c76501 -r 1fee7c6b5129 lemon/base.cc
--- a/lemon/base.cc	Tue Nov 29 08:40:03 2005 +0000
+++ b/lemon/base.cc	Tue Nov 29 08:43:50 2005 +0000
@@ -24,4 +24,6 @@
   double Tolerance<double>::def_epsilon = 1e-10;
   float Tolerance<float>::def_epsilon = 1e-4;
 
+  const Invalid INVALID = Invalid();
+
 } //namespace lemon