new file mode 100644
--- /dev/null
+++ b/src/pt-binop.cc
@@ -0,0 +1,226 @@
+/*
+
+Copyright (C) 1996, 1997 John W. Eaton
+
+This file is part of Octave.
+
+Octave 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, or (at your option) any
+later version.
+
+Octave 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 Octave; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#if defined (__GNUG__)
+#pragma implementation
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "error.h"
+#include "oct-obj.h"
+#include "ov.h"
+#include "pt-binop.h"
+#include "pt-pr-code.h"
+#include "pt-walk.h"
+
+// Binary expressions.
+ 
+octave_value_list
+tree_binary_expression::rvalue (int nargout)
+{
+  octave_value_list retval;
+
+  if (nargout > 1)
+    error ("binary operator `%s': invalid number of output arguments",
+	   oper () . c_str ());
+  else
+    retval = rvalue ();
+
+  return retval;
+}
+
+octave_value
+tree_binary_expression::rvalue (void)
+{
+  octave_value retval;
+
+  if (error_state)
+    return retval;
+
+  if (op_lhs)
+    {
+      octave_value a = op_lhs->rvalue ();
+
+      if (error_state)
+	eval_error ();
+      else if (a.is_defined () && op_rhs)
+	{
+	  octave_value b = op_rhs->rvalue ();
+
+	  if (error_state)
+	    eval_error ();
+	  else if (b.is_defined ())
+	    {
+	      retval = ::do_binary_op (etype, a, b);
+
+	      if (error_state)
+		{
+		  retval = octave_value ();
+		  eval_error ();
+		}
+	    }
+	  else
+	    eval_error ();
+	}
+      else
+	eval_error ();
+    }
+  else
+    eval_error ();
+
+  return retval;
+}
+
+void
+tree_binary_expression::eval_error (void)
+{
+  if (error_state > 0)
+    ::error ("evaluating binary operator `%s' near line %d, column %d",
+	     oper () . c_str (), line (), column ());
+}
+
+string
+tree_binary_expression::oper (void) const
+{
+  return octave_value::binary_op_as_string (etype);
+}
+
+void
+tree_binary_expression::accept (tree_walker& tw)
+{
+  tw.visit_binary_expression (*this);
+}
+
+// Boolean expressions.
+ 
+octave_value_list
+tree_boolean_expression::rvalue (int nargout)
+{
+  octave_value_list retval;
+
+  if (nargout > 1)
+    error ("binary operator `%s': invalid number of output arguments",
+	   oper () . c_str ());
+  else
+    retval = rvalue ();
+
+  return retval;
+}
+
+octave_value
+tree_boolean_expression::rvalue (void)
+{
+  octave_value retval;
+
+  if (error_state)
+    return retval;
+
+  bool result = false;
+
+  if (op_lhs)
+    {
+      octave_value a = op_lhs->rvalue ();
+
+      if (error_state)
+	eval_error ();
+      else
+	{
+	  bool a_true = a.is_true ();
+
+	  if (error_state)
+	    eval_error ();
+	  else
+	    {
+	      if (a_true)
+		{
+		  if (etype == bool_or)
+		    {
+		      result = true;
+		      goto done;
+		    }
+		}
+	      else
+		{
+		  if (etype == bool_and)
+		    goto done;
+		}
+
+	      if (op_rhs)
+		{
+		  octave_value b = op_rhs->rvalue ();
+
+		  if (error_state)
+		    eval_error ();
+		  else
+		    {
+		      result = b.is_true ();
+
+		      if (error_state)
+			eval_error ();
+		    }
+		}
+	      else
+		eval_error ();
+
+	    done:
+
+	      if (! error_state)
+		retval = octave_value (static_cast<double> (result));
+	    }
+	}
+    }
+  else
+    eval_error ();
+
+  return retval;
+}
+
+string
+tree_boolean_expression::oper (void) const
+{
+  string retval = "<unknown>";
+
+  switch (etype)
+    {
+    case bool_and:
+      retval = "&&";
+      break;
+
+    case bool_or:
+      retval = "||";
+      break;
+
+    default:
+      break;
+    }
+
+  return retval;
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/