ADDED   mttroot/mtt/lib/cr/r/cr.cr
Index: mttroot/mtt/lib/cr/r/cr.cr
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/cr/r/cr.cr
@@ -0,0 +1,39 @@
+%SUMMARY cr generic CR
+%DESCRIPTION Argument is an algebraic expression with no embeddedwhite space
+%DESCRIPTION Only available for one ports just now
+%DESCRIPTION effort (or integrated effort) variable must be called mtt_e
+%DESCRIPTION flow (or integrated flow) variable must be called mtt_f
+%DESCRIPTION For example:
+%DESCRIPTION             mtt_e=k*mtt_f
+%DESCRIPTION             mtt_f=mtt_e/r
+
+% $Log$
+
+%Copyright (C) 2000 by Peter J. Gawthrop
+
+% Version for one-port components
+operator cr;
+
+% We need four versions so that state does not need to be explicitly
+% mentioned.
+% At the moment, assume only one solution (in fact the first is
+chosen)
+
+% Flow input
+FOR ALL mtt_cr, input, out_cause
+LET cr(mtt_cr,out_cause, 1, input, flow, 1) = sub(mtt_f=input,rhs(first(solve(mtt_cr,mtt_e))));
+
+% Effort input
+FOR ALL mtt_cr, input, out_cause
+LET cr(mtt_cr,out_cause, 1, input, effort, 1) = sub(mtt_e=input,rhs(first(solve(mtt_cr,mtt_f))));
+
+% Effort output
+FOR ALL mtt_cr, input, in_cause
+LET cr(mtt_cr,effort, 1, input, in_cause, 1) = sub(mtt_f=input,rhs(first(solve(mtt_cr,mtt_e))));
+
+% Flow output
+FOR ALL mtt_cr, input, in_cause
+LET cr(mtt_cr,flow, 1, input, in_cause, 1) = sub(mtt_e=input,rhs(first(solve(mtt_cr,mtt_f))));
+
+
+END;