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diff --git a/testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/opamp-1.vhd b/testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/opamp-1.vhd
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+
+-- Copyright (C) 2002 Morgan Kaufmann Publishers, Inc
+
+-- This file is part of VESTs (Vhdl tESTs).
+
+-- VESTs is free software; you can redistribute it and/or modify it
+-- under the terms of the GNU General Public License as published by the
+-- Free Software Foundation; either version 2 of the License, or (at
+-- your option) any later version. 
+
+-- VESTs is distributed in the hope that it will be useful, but WITHOUT
+-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+-- FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+-- for more details. 
+
+-- You should have received a copy of the GNU General Public License
+-- along with VESTs; if not, write to the Free Software Foundation,
+-- Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+
+library ieee_proposed;  use ieee_proposed.electrical_systems.all;
+                        
+entity opamp is
+  port ( terminal positive_supply, negative_supply : electrical;
+         terminal plus_in, minus_in, output : electrical );
+end entity opamp;
+
+----------------------------------------------------------------
+
+architecture saturating of opamp is
+  
+  constant gain : real := 50.0;
+  quantity v_pos across positive_supply;
+  quantity v_neg across negative_supply;
+  quantity v_in across plus_in to minus_in;
+  quantity v_out across i_out through output;
+  quantity v_amplified : voltage;
+  
+begin
+  
+  if v_in'above(v_pos / gain) use 
+    v_amplified == v_pos;
+  elsif not v_in'above(v_neg / gain) use
+    v_amplified == v_neg;
+  else 
+    v_amplified == gain * v_in;
+  end use;
+        
+  break on v_in'above(v_pos/gain), v_in'above(v_neg/gain);
+        
+  v_out == v_amplified'slew(1.0e6,-1.0e6);
+        
+end architecture saturating;