ADDED   mttroot/mtt/lib/comp/simple/SS_cause.m
Index: mttroot/mtt/lib/comp/simple/SS_cause.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/SS_cause.m
@@ -0,0 +1,35 @@
+function [bonds,status] = SS_cause(bonds)
+% SS_cause = causality for an SS component
+% 
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+%     %%%%% Model Transformation Tools %%%%%
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 
+% Matlab function  SS_cause
+% [bonds,status] = SS_cause(bonds)
+
+%SUMMARY SS: source-sensor component
+%DESCRIPTION one-port source sensor component
+%DESCRIPTION when the name is [i], acts as ith port of a system.
+%DESCRIPTION may be bicausal
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Copyright (c) P.J. Gawthrop, 1996.
+
+if (bonds(1)==0)|(bonds(2)==0) % Under causal
+  status = -1;
+else                          % causal
+  status = 0;
+end;
+
+
+
+
+