+#ifndef ENVIRONMENT_HH
+#define ENVIRONMENT_HH
+
+
+#include "tlib.hh"
+
+Tree pushValueDef(Tree id, Tree def, Tree lenv);
+
+bool searchIdDef(Tree id, Tree& def, Tree lenv);
+
+Tree pushMultiClosureDefs(Tree ldefs, Tree visited, Tree lenv);
+
+Tree copyEnvReplaceDefs(Tree anEnv, Tree ldefs, Tree visited, Tree curEnv);
+
+bool isEnvBarrier(Tree t);
+
+Tree pushEnvBarrier(Tree lenv);
+
+
+#endif // ENVIRONMENT_HH