ADDED   mttroot/mtt/lib/comp/simple/Amp_seqn.m
Index: mttroot/mtt/lib/comp/simple/Amp_seqn.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/Amp_seqn.m
@@ -0,0 +1,43 @@
+function [eqn,insigs,innames] = Amp_seqn (AmpType,Name, name, cr, arg, outsig, insigs, innames)
+
+  ## usage:  [eqn,inbonds] = AF_seqn (Name, cr, arg, outbond, inbonds)
+  ##
+  ## 
+
+  N = mtt_check_sigs (outsig,insigs);
+  if (N!=2)
+    mtt_error("Amplifier component must have exactly two ports");
+  endif
+  
+
+  ## On which port is the equation required?
+  outbond_number = outsig(1);
+  outport = find(abs(insigs(:,1))!=outbond_number*ones(N,1));
+
+  ## Some definitions
+  flow = -1;
+  effort = 1;
+
+  if strcmp(AmpType,"AE")
+    causality = effort;
+    other_causality = flow;
+  elseif strcmp(AmpType,"AF")
+    causality = flow;
+    other_causality = effort;
+  else
+    mtt_error(sprintf("Amp_seqn: type %s unknown", AmpType));
+  endif
+  
+  ## Standard causality
+  if (outport==2)
+    qAmpType = sprintf("""%s""", AmpType);
+    eqn = equation(qAmpType,Name,cr,arg,outsig(1),causality,2, ...
+		 insigs(2,1),causality,1);
+  elseif (outport==1)
+    LHS = varname(Name,insigs(2,1),other_causality);
+    eqn = sprintf("%s := 0;", LHS);
+  else
+    mtt_error("AF_seqn: outport must be 1 or 2");
+  endif
+
+endfunction