diff --git a/PExpr.cc b/PExpr.cc
index db1e00a6b..f5b8f94ea 100644
--- a/PExpr.cc
+++ b/PExpr.cc
@@ -17,17 +17,35 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: PExpr.cc,v 1.1 1998/11/03 23:28:53 steve Exp $"
+#ident "$Id: PExpr.cc,v 1.2 1998/11/11 00:01:51 steve Exp $"
 #endif
 
 # include  "PExpr.h"
+# include  <typeinfo>
 
 PExpr::~PExpr()
 {
 }
 
+bool PExpr::is_the_same(const PExpr*that) const
+{
+      return typeid(this) == typeid(that);
+}
+
+bool PENumber::is_the_same(const PExpr*that) const
+{
+      const PENumber*obj = dynamic_cast<const PENumber*>(that);
+      if (obj == 0)
+	    return false;
+
+      return *value_ == *obj->value_;
+}
+
 /*
  * $Log: PExpr.cc,v $
+ * Revision 1.2  1998/11/11 00:01:51  steve
+ *  Check net ranges in declarations.
+ *
  * Revision 1.1  1998/11/03 23:28:53  steve
  *  Introduce verilog to CVS.
  *
diff --git a/PExpr.h b/PExpr.h
index 7e21d88b5..e2e84c272 100644
--- a/PExpr.h
+++ b/PExpr.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: PExpr.h,v 1.3 1998/11/09 18:55:33 steve Exp $"
+#ident "$Id: PExpr.h,v 1.4 1998/11/11 00:01:51 steve Exp $"
 #endif
 
 # include  <string>
@@ -50,6 +50,11 @@ class PExpr {
 	// a verinum as a result. If the expression cannot be
 	// evaluated, return 0.
       virtual verinum* eval_const() const;
+
+	// This method returns true if that expression is the same as
+	// this expression. This method is used for comparing
+	// expressions that must be structurally "identical".
+      virtual bool is_the_same(const PExpr*that) const;
 };
 
 ostream& operator << (ostream&, const PExpr&);
@@ -88,6 +93,8 @@ class PENumber : public PExpr {
       virtual NetExpr*elaborate_expr(Design*des, const string&path) const;
       virtual verinum* eval_const() const;
 
+      virtual bool is_the_same(const PExpr*that) const;
+
     private:
       verinum*const value_;
 };
@@ -139,6 +146,9 @@ class PEBinary : public PExpr {
 
 /*
  * $Log: PExpr.h,v $
+ * Revision 1.4  1998/11/11 00:01:51  steve
+ *  Check net ranges in declarations.
+ *
  * Revision 1.3  1998/11/09 18:55:33  steve
  *  Add procedural while loops,
  *  Parse procedural for loops,
diff --git a/parse.y b/parse.y
index 77e0435ee..6ed8d0a51 100644
--- a/parse.y
+++ b/parse.y
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: parse.y,v 1.3 1998/11/09 18:55:34 steve Exp $"
+#ident "$Id: parse.y,v 1.4 1998/11/11 00:01:51 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -486,10 +486,10 @@ primitive
 	;
 
 range
-	: '[' NUMBER ':' NUMBER ']'
+	: '[' const_expression ':' const_expression ']'
 		{ list<PExpr*>*tmp = new list<PExpr*>;
-		  tmp->push_back(new PENumber($2));
-		  tmp->push_back(new PENumber($4));
+		  tmp->push_back($2);
+		  tmp->push_back($4);
 		  $$ = tmp;
 		}
 	;
diff --git a/pform.cc b/pform.cc
index 357a60cdb..cb6538537 100644
--- a/pform.cc
+++ b/pform.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: pform.cc,v 1.2 1998/11/07 17:05:06 steve Exp $"
+#ident "$Id: pform.cc,v 1.3 1998/11/11 00:01:51 steve Exp $"
 #endif
 
 # include  "pform.h"
@@ -211,7 +211,14 @@ static void pform_set_net_range(const string&name, list<PExpr*>*range)
 	    idx ++;
 	    cur->lsb = *idx;
       } else {
-	    VLwarn(yylloc, "net ranges not checked.");
+	    list<PExpr*>::const_iterator idx = range->begin();
+	    PExpr*msb = *idx;
+	    idx ++;
+	    PExpr*lsb = *idx;
+	    if (! (cur->msb->is_the_same(msb) && cur->lsb->is_the_same(lsb)))
+		  VLerror(yylloc, "net ranges are not identical.");
+	    delete msb;
+	    delete lsb;
       }
 }
 
@@ -286,6 +293,9 @@ int pform_parse(FILE*input, list<Module*>&modules)
 
 /*
  * $Log: pform.cc,v $
+ * Revision 1.3  1998/11/11 00:01:51  steve
+ *  Check net ranges in declarations.
+ *
  * Revision 1.2  1998/11/07 17:05:06  steve
  *  Handle procedural conditional, and some
  *  of the conditional expressions.
diff --git a/verinum.cc b/verinum.cc
index 316b0d944..391e1b28f 100644
--- a/verinum.cc
+++ b/verinum.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: verinum.cc,v 1.4 1998/11/09 19:03:26 steve Exp $"
+#ident "$Id: verinum.cc,v 1.5 1998/11/11 00:01:51 steve Exp $"
 #endif
 
 # include  "verinum.h"
@@ -207,8 +207,23 @@ ostream& operator<< (ostream&o, const verinum&v)
       return o;
 }
 
+bool operator == (const verinum&left, const verinum&right)
+{
+      if (left.len() != right.len())
+	    return false;
+
+      for (unsigned idx = 0 ;  idx < left.len() ;  idx += 1)
+	    if (left[idx] != right[idx])
+		  return false;
+
+      return true;
+}
+
 /*
  * $Log: verinum.cc,v $
+ * Revision 1.5  1998/11/11 00:01:51  steve
+ *  Check net ranges in declarations.
+ *
  * Revision 1.4  1998/11/09 19:03:26  steve
  *  Oops, forgot return from operator<<
  *
diff --git a/verinum.h b/verinum.h
index d25655356..a42162846 100644
--- a/verinum.h
+++ b/verinum.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: verinum.h,v 1.2 1998/11/09 18:55:35 steve Exp $"
+#ident "$Id: verinum.h,v 1.3 1998/11/11 00:01:51 steve Exp $"
 #endif
 
 # include  <string>
@@ -73,11 +73,16 @@ class verinum {
 
 
 class ostream;
-ostream& operator<< (ostream&, const verinum&);
-ostream& operator<< (ostream&, verinum::V);
+extern ostream& operator<< (ostream&, const verinum&);
+extern ostream& operator<< (ostream&, verinum::V);
+
+extern bool operator == (const verinum&left, const verinum&right);
 
 /*
  * $Log: verinum.h,v $
+ * Revision 1.3  1998/11/11 00:01:51  steve
+ *  Check net ranges in declarations.
+ *
  * Revision 1.2  1998/11/09 18:55:35  steve
  *  Add procedural while loops,
  *  Parse procedural for loops,