ADDED   mttroot/mtt/lib/comp/simple/ES_cause.m
Index: mttroot/mtt/lib/comp/simple/ES_cause.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/ES_cause.m
@@ -0,0 +1,30 @@
+function [bonds,status] = ES_cause(bonds);
+% Causality for ES component
+
+%SUMMARY ES: converts thermal pseudobond to true bond and vv
+%DESCRIPTION Port [e]: temperature (T) / enthalpy flow (E) bond
+%DESCRIPTION Port [s]: temperature (T) / entropy flow (S) bond
+
+
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Copyright (c) P.J. Gawthrop, 1997.
+
+status = -1;
+
+% Check that there are exactly two bonds.
+if check_bonds(bonds,2,'ES')==0
+  return
+end
+
+% Same causality as TF
+[bonds,status] = TF_cause(bonds);
+
+