diff --git a/PExpr.h b/PExpr.h
index 1a0140c65..1095795bd 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 1.6 1999/04/29 02:16:26 steve Exp $"
+#ident "$Id: PExpr.h,v 1.7 1999/05/01 02:57:52 steve Exp $"
 #endif
 
 # include  <string>
@@ -64,17 +64,17 @@ ostream& operator << (ostream&, const PExpr&);
 class PEEvent : public PExpr {
 
     public:
-      PEEvent(NetPEvent::Type t, PExpr*e)
+      PEEvent(NetNEvent::Type t, PExpr*e)
       : type_(t), expr_(e)
       { }
 
-      NetPEvent::Type type() const { return type_; }
+      NetNEvent::Type type() const { return type_; }
       PExpr*          expr() const { return expr_; }
 
       virtual void dump(ostream&) const;
 
     private:
-      NetPEvent::Type type_;
+      NetNEvent::Type type_;
       PExpr*expr_;
 };
 
@@ -169,6 +169,9 @@ class PEBinary : public PExpr {
 
 /*
  * $Log: PExpr.h,v $
+ * Revision 1.7  1999/05/01 02:57:52  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.6  1999/04/29 02:16:26  steve
  *  Parse OR of event expressions.
  *
diff --git a/design_dump.cc b/design_dump.cc
index 0932eadcf..16bd5bd4d 100644
--- a/design_dump.cc
+++ b/design_dump.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: design_dump.cc,v 1.18 1999/04/25 00:44:10 steve Exp $"
+#ident "$Id: design_dump.cc,v 1.19 1999/05/01 02:57:52 steve Exp $"
 #endif
 
 /*
@@ -246,7 +246,7 @@ void NetUDP::dump_node(ostream&o, unsigned ind) const
 	    dump_comb_(o, ind);
 }
 
-void NetPEvent::dump_node(ostream&o, unsigned ind) const
+void NetNEvent::dump_node(ostream&o, unsigned ind) const
 {
       o << setw(ind) << "" << "event: ";
       switch (edge_) {
@@ -360,21 +360,15 @@ void NetPDelay::dump(ostream&o, unsigned ind) const
 
 void NetPEvent::dump(ostream&o, unsigned ind) const
 {
-      o << setw(ind) << "" ;
-      switch (edge_) {
-	  case NEGEDGE:
-	    o << "@" << "(negedge " << name() << ")";
-	    break;
-	  case POSEDGE:
-	    o << "@" << "(posedge " << name() << ")";
-	    break;
-	  case ANYEDGE:
-	    o << "@" << name();
-	    break;
-	  case POSITIVE:
-	    o << "wait (" << name() << ")";
-	    break;
+      o << setw(ind) << "" << "@(";
+      svector<const NetNEvent*>*list = back_list();
+      (*list)[0]->dump_proc(o);
+      for (unsigned idx = 1 ;  idx < list->count() ;  idx += 1) {
+	    o << " or ";
+	    (*list)[idx]->dump_proc(o);
       }
+      delete list;
+      o << ") /* " << name_ << " */";
 
       if (statement_) {
 	    o << endl;
@@ -384,7 +378,24 @@ void NetPEvent::dump(ostream&o, unsigned ind) const
       }
 }
 
-
+void NetNEvent::dump_proc(ostream&o) const
+{
+      switch (edge_) {
+	  case ANYEDGE:
+	    o << "anyedge ";
+	    break;
+	  case POSEDGE:
+	    o << "posedge ";
+	    break;
+	  case NEGEDGE:
+	    o << "negedge ";
+	    break;
+	  case POSITIVE:
+	    o << "positive ";
+	    break;
+      }
+      o << name();
+}
 
 void NetTask::dump(ostream&o, unsigned ind) const
 {
@@ -551,6 +562,9 @@ void Design::dump(ostream&o) const
 
 /*
  * $Log: design_dump.cc,v $
+ * Revision 1.19  1999/05/01 02:57:52  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.18  1999/04/25 00:44:10  steve
  *  Core handles subsignal expressions.
  *
diff --git a/elaborate.cc b/elaborate.cc
index 492f387e5..0e6042f40 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: elaborate.cc,v 1.21 1999/04/29 02:16:26 steve Exp $"
+#ident "$Id: elaborate.cc,v 1.22 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 /*
@@ -882,29 +882,28 @@ NetProc* PEventStatement::elaborate(Design*des, const string&path) const
 		  return 0;
       }
 
-      if (expr_.count() != 1) {
-	    cerr << get_line() << ": Sorry, unable to elaborate event "
-		  "OR expressions." << endl;
-	    des->errors += 1;
-	    return 0;
+	/* Create a single NetPEvent, and a unique NetNEvent for each
+	   conjuctive event. */
+
+      NetPEvent*pe = new NetPEvent(des->local_symbol(path), enet);
+      for (unsigned idx = 0 ;  idx < expr_.count() ;  idx += 1) {
+	    NetNet*expr = expr_[idx]->expr()->elaborate_net(des, path);
+	    if (expr == 0) {
+		  cerr << get_line() << ": Failed to elaborate expression: ";
+		  expr_[0]->dump(cerr);
+		  cerr << endl;
+		  delete pe;
+		  return 0;
+	    }
+	    assert(expr);
+	    NetNEvent*ne = new NetNEvent(des->local_symbol(path),
+					 expr_[idx]->type(), pe);
+
+	    connect(ne->pin(0), expr->pin(0));
+	    des->add_node(ne);
       }
 
-      NetPEvent*ev = new NetPEvent(des->local_symbol(path),
-				   expr_[0]->type(), enet);
-
-      NetNet*expr = expr_[0]->expr()->elaborate_net(des, path);
-      if (expr == 0) {
-	    cerr << get_line() << ": Failed to elaborate expression: ";
-	    expr_[0]->dump(cerr);
-	    cerr << endl;
-	    delete ev;
-	    return 0;
-      }
-      assert(expr);
-      connect(ev->pin(0), expr->pin(0));
-
-      des->add_node(ev);
-      return ev;
+      return pe;
 }
 
 /*
@@ -1051,6 +1050,9 @@ Design* elaborate(const map<string,Module*>&modules,
 
 /*
  * $Log: elaborate.cc,v $
+ * Revision 1.22  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.21  1999/04/29 02:16:26  steve
  *  Parse OR of event expressions.
  *
diff --git a/emit.cc b/emit.cc
index 9fdfe33a3..cd3a2bda4 100644
--- a/emit.cc
+++ b/emit.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: emit.cc,v 1.8 1999/04/25 00:44:10 steve Exp $"
+#ident "$Id: emit.cc,v 1.9 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 /*
@@ -55,9 +55,9 @@ void NetConst::emit_node(ostream&o, struct target_t*tgt) const
       tgt->net_const(o, this);
 }
 
-void NetPEvent::emit_node(ostream&o, struct target_t*tgt) const
+void NetNEvent::emit_node(ostream&o, struct target_t*tgt) const
 {
-      tgt->net_pevent(o, this);
+      tgt->net_event(o, this);
 }
 
 void NetBUFZ::emit_node(ostream&o, struct target_t*tgt) const
@@ -253,6 +253,9 @@ void emit(ostream&o, const Design*des, const char*type)
 
 /*
  * $Log: emit.cc,v $
+ * Revision 1.9  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.8  1999/04/25 00:44:10  steve
  *  Core handles subsignal expressions.
  *
diff --git a/netlist.cc b/netlist.cc
index 37dce1348..cbfcbb33a 100644
--- a/netlist.cc
+++ b/netlist.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-1999 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: netlist.cc,v 1.21 1999/04/25 00:44:10 steve Exp $"
+#ident "$Id: netlist.cc,v 1.22 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  <cassert>
@@ -480,6 +480,7 @@ void NetEBinary::set_width(unsigned w)
 
 	  case '+':
 	  case '-':
+	  case '^':
 	    left_->set_width(w);
 	    right_->set_width(w);
 	    expr_width(w);
@@ -532,6 +533,11 @@ NetESignal::~NetESignal()
 
 void NetESignal::set_width(unsigned w)
 {
+      if (w != pin_count()) {
+	    cerr << "Width of " << w << " does not match " << *this <<
+		  endl;
+	    abort();
+      }
       assert(w == pin_count());
       expr_width(w);
 }
@@ -553,7 +559,15 @@ NetEUnary::~NetEUnary()
 
 void NetEUnary::set_width(unsigned w)
 {
-      expr_->set_width(w);
+      switch (op_) {
+	  case '&':
+	    assert(w == 1);
+	    break;
+	  default:
+	  case '~':
+	    expr_->set_width(w);
+	    break;
+      }
       expr_width(w);
 }
 
@@ -1026,6 +1040,9 @@ NetNet* Design::find_signal(bool (*func)(const NetNet*))
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.22  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.21  1999/04/25 00:44:10  steve
  *  Core handles subsignal expressions.
  *
diff --git a/netlist.h b/netlist.h
index 005845d98..9856dbdf6 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: netlist.h,v 1.26 1999/04/25 22:52:32 steve Exp $"
+#ident "$Id: netlist.h,v 1.27 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 /*
@@ -31,6 +31,7 @@
 # include  <string>
 # include  <map>
 # include  "verinum.h"
+# include  "sref.h"
 # include  "LineInfo.h"
 
 class NetNode;
@@ -715,33 +716,55 @@ class NetPDelay  : public NetProc {
 };
 
 /*
- * The NetPEvent is a NetNode that connects to the structural part of
- * the design. It has only inputs, which cause the side effect of
- * triggering an event that the procedural part of the design can use.
+ * The NetPEvent is associated with NetNEvents. The NetPEvent receives
+ * eventss from any one of the associated NetNEvents and in response
+ * causes the attached statement to be executed. Objects of this type
+ * are not nodes, but require a name anyhow so that backends can
+ * generate objects to refer to it.
  */
-class NetPEvent  : public NetProc, public NetNode {
+class NetNEvent;
+class NetPEvent : public NetProc, public sref_back<NetPEvent,NetNEvent> {
 
     public:
-      enum Type { ANYEDGE, POSEDGE, NEGEDGE, POSITIVE };
+      NetPEvent(const string&n, NetProc*st)
+      : name_(n), statement_(st) { }
 
-    public:
-      NetPEvent(const string&ev, Type ed, NetProc*st)
-      : NetNode(ev, 1), edge_(ed), statement_(st) { }
-
-      Type   edge() const  { return edge_; }
+      string name() const { return name_; }
 
       virtual void emit_proc(ostream&, struct target_t*) const;
-      virtual void emit_node(ostream&, struct target_t*) const;
       virtual void dump(ostream&, unsigned ind) const;
-      virtual void dump_node(ostream&, unsigned ind) const;
 
       void emit_proc_recurse(ostream&, struct target_t*) const;
 
     private:
-      Type edge_;
+      string name_;
       NetProc*statement_;
 };
 
+/*
+ * The NetNEvent is a NetNode that connects to the structural part of
+ * the design. It has only inputs, which cause the side effect of
+ * triggering an event that the procedural part of the design can use.
+ */
+class NetNEvent  : public NetNode, public sref<NetPEvent,NetNEvent> {
+
+    public:
+      enum Type { ANYEDGE, POSEDGE, NEGEDGE, POSITIVE };
+
+      NetNEvent(const string&ev, Type e, NetPEvent*pe)
+      : NetNode(ev, 1), sref<NetPEvent,NetNEvent>(pe), edge_(e) { }
+
+      Type type() const { return edge_; }
+
+      virtual void emit_node(ostream&, struct target_t*) const;
+
+      void dump_proc(ostream&) const;
+      virtual void dump_node(ostream&, unsigned ind) const;
+
+    private:
+      Type edge_;
+};
+
 
 /* The elaborator should expand all the user defined tasks in line, so
    this leaves the NetTask to represent activations of system tasks,
@@ -1129,6 +1152,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.27  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.26  1999/04/25 22:52:32  steve
  *  Generate SubSignal refrences in vvm.
  *
diff --git a/parse.y b/parse.y
index 1bb95e022..227f2fda0 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 1.18 1999/04/29 02:16:26 steve Exp $"
+#ident "$Id: parse.y,v 1.19 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -241,7 +241,7 @@ event_control
 
 event_expression
 	: K_posedge expression
-		{ PEEvent*tmp = new PEEvent(NetPEvent::POSEDGE, $2);
+		{ PEEvent*tmp = new PEEvent(NetNEvent::POSEDGE, $2);
 		  tmp->set_file(@1.text);
 		  tmp->set_lineno(@1.first_line);
 		  svector<PEEvent*>*tl = new svector<PEEvent*>(1);
@@ -249,7 +249,7 @@ event_expression
 		  $$ = tl;
 		}
 	| K_negedge expression
-		{ PEEvent*tmp = new PEEvent(NetPEvent::NEGEDGE, $2);
+		{ PEEvent*tmp = new PEEvent(NetNEvent::NEGEDGE, $2);
 		  tmp->set_file(@1.text);
 		  tmp->set_lineno(@1.first_line);
 		  svector<PEEvent*>*tl = new svector<PEEvent*>(1);
@@ -257,7 +257,7 @@ event_expression
 		  $$ = tl;
 		}
 	| expression
-		{ PEEvent*tmp = new PEEvent(NetPEvent::ANYEDGE, $1);
+		{ PEEvent*tmp = new PEEvent(NetNEvent::ANYEDGE, $1);
 		  tmp->set_file(@1.text);
 		  tmp->set_lineno(@1.first_line);
 		  svector<PEEvent*>*tl = new svector<PEEvent*>(1);
@@ -776,7 +776,7 @@ statement
 		}
 	| K_wait '(' expression ')' statement_opt
 		{ PEventStatement*tmp;
-		  PEEvent*etmp = new PEEvent(NetPEvent::POSITIVE, $3);
+		  PEEvent*etmp = new PEEvent(NetNEvent::POSITIVE, $3);
 		  tmp = new PEventStatement(etmp);
 		  tmp->set_statement($5);
 		  $$ = tmp;
diff --git a/pform_dump.cc b/pform_dump.cc
index 291d3056c..cfddcda6f 100644
--- a/pform_dump.cc
+++ b/pform_dump.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: pform_dump.cc,v 1.13 1999/04/29 02:16:26 steve Exp $"
+#ident "$Id: pform_dump.cc,v 1.14 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 /*
@@ -45,15 +45,15 @@ void PExpr::dump(ostream&out) const
 void PEEvent::dump(ostream&out) const
 {
       switch (type_) {
-	  case NetPEvent::ANYEDGE:
+	  case NetNEvent::ANYEDGE:
 	    break;
-	  case NetPEvent::POSEDGE:
+	  case NetNEvent::POSEDGE:
 	    out << "posedge ";
 	    break;
-	  case NetPEvent::NEGEDGE:
+	  case NetNEvent::NEGEDGE:
 	    out << "negedge ";
 	    break;
-	  case NetPEvent::POSITIVE:
+	  case NetNEvent::POSITIVE:
 	    out << "positive ";
 	    break;
       }
@@ -434,6 +434,9 @@ void PUdp::dump(ostream&out) const
 
 /*
  * $Log: pform_dump.cc,v $
+ * Revision 1.14  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.13  1999/04/29 02:16:26  steve
  *  Parse OR of event expressions.
  *
diff --git a/sref.h b/sref.h
new file mode 100644
index 000000000..1d4a518af
--- /dev/null
+++ b/sref.h
@@ -0,0 +1,111 @@
+#ifndef __sref_H
+#define __sref_H
+/*
+ * Copyright (c) 1999 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form 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. In order to redistribute the software in
+ *    binary form, you will need a Picture Elements Binary Software
+ *    License.
+ *
+ *    This program 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 this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+#if !defined(WINNT)
+#ident "$Id: sref.h,v 1.1 1999/05/01 02:57:53 steve Exp $"
+#endif
+
+# include  <assert.h>
+# include  "svector.h"
+
+/*
+ * The sref class is a reference with automatic reference counting. It
+ * implementes a many-to-one linkage where T1 is the many type and T2
+ * is the one type.
+ */
+
+template <class T1, class T2> class sref;
+template <class T1, class T2> class sref_back;
+
+template <class T1, class T2> class sref_back {
+
+      friend class sref<T1,T2>;
+
+    public:
+      sref_back() : sback_(0) { }
+      ~sref_back() { assert(sback_ == 0); }
+
+      svector<const T2*>* back_list() const;
+
+    private:
+      sref<T1,T2>*sback_;
+};
+
+template <class T1, class T2> class sref {
+
+      friend class sref_back<T1,T2>;
+
+    public:
+      sref(T1*d) : dest_(d) { insert_(); }
+      virtual ~sref() { desert_(); }
+
+      T1*fore_ptr() { return dest_; }
+      const T1*fore_ptr() const { return dest_; }
+
+    private:
+      T1*dest_;
+      sref<T1,T2>*next_;
+
+      void insert_()
+	    { if (dest_->sback_ == 0) {
+		    next_ = this;
+		    dest_->sback_ = this;
+	      } else {
+		    next_ = dest_->sback_->next_;
+		    dest_->sback_->next_ = this;
+	      }
+	    }
+
+	// Not implemented yet.
+      void desert_() { assert(0); }
+};
+
+template <class T1,class T2>
+svector<const T2*>* sref_back<T1,T2>::back_list() const
+{
+      if (sback_ == 0) return 0;
+      unsigned cnt = 1;
+      sref<T1,T2>*cur = sback_->next_;
+      while (cur != sback_) {
+	    cnt += 1;
+	    cur = cur->next_;
+      }
+
+      svector<const T2*>* result = new svector<const T2*>(cnt);
+      (*result)[0] = dynamic_cast<const T2*>(sback_);
+      cur = sback_->next_;
+      cnt = 1;
+      while (cur != sback_) {
+	    (*result)[cnt] = dynamic_cast<const T2*>(cur);
+	    cnt += 1;
+	    cur = cur->next_;
+      }
+      return result;
+}
+
+/*
+ * $Log: sref.h,v $
+ * Revision 1.1  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
+ */
+#endif
diff --git a/svector.h b/svector.h
index 066ef02e2..3ef31ae23 100644
--- a/svector.h
+++ b/svector.h
@@ -1,8 +1,7 @@
 #ifndef __svector_H
 #define __svector_H
 /*
- * Copyright (c) 1999 Picture Elements, Inc.
- *    Stephen Williams (steve@picturel.com)
+ * Copyright (c) 1999 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -20,15 +19,9 @@
  *    You should have received a copy of the GNU General Public License
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- *  ---
- *    You should also have recieved a copy of the Picture Elements
- *    Binary Software License offer along with the source. This offer
- *    allows you to obtain the right to redistribute the software in
- *    binary (compiled) form. If you have not received it, contact
- *    Picture Elements, Inc., 777 Panoramic Way, Berkeley, CA 94704.
  */
 #if !defined(WINNT)
-#ident "$Id: svector.h,v 1.1 1999/04/29 02:16:26 steve Exp $"
+#ident "$Id: svector.h,v 1.2 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  <assert.h>
@@ -87,6 +80,9 @@ template <class TYPE> class svector {
 
 /*
  * $Log: svector.h,v $
+ * Revision 1.2  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.1  1999/04/29 02:16:26  steve
  *  Parse OR of event expressions.
  *
diff --git a/t-verilog.cc b/t-verilog.cc
index 261141913..0b45e6da7 100644
--- a/t-verilog.cc
+++ b/t-verilog.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: t-verilog.cc,v 1.3 1998/12/01 00:42:15 steve Exp $"
+#ident "$Id: t-verilog.cc,v 1.4 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 /*
@@ -222,21 +222,25 @@ void target_verilog::proc_event(ostream&os, const NetPEvent*net)
 {
       os << setw(indent_) << "" << "@";
 
+#if 0
       unsigned sidx;
       const NetNet*sig = find_link_signal(net, 0, sidx);
 
       switch (net->edge()) {
-	  case NetPEvent::ANYEDGE:
+	  case NetNEvent::ANYEDGE:
 	    os << mangle(sig->name()) << "[" << sidx << "]";
 	    break;
-	  case NetPEvent::POSEDGE:
+	  case NetNEvent::POSEDGE:
 	    os << "(posedge " << mangle(sig->name()) << "[" << sidx << "])";
 	    break;
-	  case NetPEvent::NEGEDGE:
+	  case NetNEvent::NEGEDGE:
 	    os << "(negedge " << mangle(sig->name()) << "[" << sidx << "])";
 	    break;
       }
-
+#else
+      os << endl;
+      os << "#error \"proc_event temporarily out of order\"";
+#endif
       os << endl;
 
       indent_ += 4;
@@ -294,6 +298,9 @@ const struct target tgt_verilog = {
 
 /*
  * $Log: t-verilog.cc,v $
+ * Revision 1.4  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.3  1998/12/01 00:42:15  steve
  *  Elaborate UDP devices,
  *  Support UDP type attributes, and
diff --git a/t-vvm.cc b/t-vvm.cc
index c56b3e403..da86014fd 100644
--- a/t-vvm.cc
+++ b/t-vvm.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: t-vvm.cc,v 1.17 1999/04/25 22:52:32 steve Exp $"
+#ident "$Id: t-vvm.cc,v 1.18 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  <iostream>
@@ -47,7 +47,7 @@ class target_vvm : public target_t {
       virtual void udp(ostream&os, const NetUDP*);
       virtual void net_const(ostream&os, const NetConst*);
       virtual void net_esignal(ostream&os, const NetESignal*);
-      virtual void net_pevent(ostream&os, const NetPEvent*);
+      virtual void net_event(ostream&os, const NetNEvent*);
       virtual void start_process(ostream&os, const NetProcTop*);
       virtual void proc_assign(ostream&os, const NetAssign*);
       virtual void proc_block(ostream&os, const NetBlock*);
@@ -584,7 +584,7 @@ void target_vvm::net_esignal(ostream&os, const NetESignal*net)
 }
 
 /*
- * The net_pevent device is a synthetic device type--a fabrication of
+ * The net_event device is a synthetic device type--a fabrication of
  * the elaboration phase. An event device receives value changes from
  * the attached signal. It is an input only device, its only value
  * being the side-effects that threads waiting on events can be
@@ -593,10 +593,32 @@ void target_vvm::net_esignal(ostream&os, const NetESignal*net)
  * The proc_event method handles the other half of this, the process
  * that blocks on the event.
  */
-void target_vvm::net_pevent(ostream&os, const NetPEvent*gate)
+void target_vvm::net_event(ostream&os, const NetNEvent*gate)
 {
-      os << "static vvm_pevent " << mangle(gate->name()) << ";"
-	    " /* " << gate->name() << " */" << endl;
+      string pevent = mangle(gate->fore_ptr()->name());
+      os << "  /* " << gate->name() << " */" << endl;
+
+      os << "#ifndef PEVENT_" << pevent << endl;
+      os << "#define PEVENT_" << pevent << endl;
+      os << "static vvm_sync " << pevent << ";" << endl;
+      os << "#endif" << endl;
+
+      os << "static vvm_pevent " << mangle(gate->name()) << "(&" <<
+	    pevent << ", ";
+      switch (gate->type()) {
+	  case NetNEvent::POSEDGE:
+	    os << "vvm_pevent::POSEDGE";
+	    break;
+	  case NetNEvent::NEGEDGE:
+	    os << "vvm_pevent::NEGEDGE";
+	    break;
+	  case NetNEvent::ANYEDGE:
+	    os << "vvm_pevent::ANYEDGE";
+	    break;
+	  default:
+	    assert(0);
+      }
+      os << ");" << endl;
 }
 
 void target_vvm::start_process(ostream&os, const NetProcTop*proc)
@@ -829,6 +851,7 @@ void target_vvm::proc_event(ostream&os, const NetPEvent*proc)
       thread_step_ += 1;
       os << "        step_ = &step_" << thread_step_ << "_;" << endl;
 
+#if 0
 	/* POSITIVE is for the wait construct, and needs to be handled
 	   specially. The structure of the generated code is:
 
@@ -879,7 +902,18 @@ void target_vvm::proc_event(ostream&os, const NetPEvent*proc)
       os << "      }" << endl;
       os << "      bool step_" << thread_step_ << "_()" << endl;
       os << "      {" << endl;
-
+#else
+	/* The canonical wait for an edge puts the thread into the
+	   correct wait object, then returns false from the thread to
+	   suspend execution. When things are ready to proceed, the
+	   correct vvm_pevent will send a wakeup to start the next
+	   basic block. */
+      os << "        " << mangle(proc->name()) << ".wait(this);" << endl;
+      os << "        return false;" << endl;
+      os << "      }" << endl;
+      os << "      bool step_" << thread_step_ << "_()" << endl;
+      os << "      {" << endl;
+#endif
       proc->emit_proc_recurse(os, this);
 }
 
@@ -923,6 +957,9 @@ extern const struct target tgt_vvm = {
 };
 /*
  * $Log: t-vvm.cc,v $
+ * Revision 1.18  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.17  1999/04/25 22:52:32  steve
  *  Generate SubSignal refrences in vvm.
  *
diff --git a/target.cc b/target.cc
index 57caa252e..82f649534 100644
--- a/target.cc
+++ b/target.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: target.cc,v 1.7 1999/04/25 00:44:10 steve Exp $"
+#ident "$Id: target.cc,v 1.8 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -73,10 +73,10 @@ void target_t::net_esignal(ostream&os, const NetESignal*)
 	    "Unhandled Expression Signal node." << endl;
 }
 
-void target_t::net_pevent(ostream&os, const NetPEvent*)
+void target_t::net_event(ostream&os, const NetNEvent*)
 {
       cerr << "target (" << typeid(*this).name() <<  "): "
-	    "Unhandled EVENT node." << endl;
+	    "Unhandled EVENT net node." << endl;
 }
 
 void target_t::start_process(ostream&os, const NetProcTop*)
@@ -184,6 +184,9 @@ void expr_scan_t::expr_binary(const NetEBinary*ex)
 
 /*
  * $Log: target.cc,v $
+ * Revision 1.8  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.7  1999/04/25 00:44:10  steve
  *  Core handles subsignal expressions.
  *
diff --git a/target.h b/target.h
index cc92c1411..587dd595e 100644
--- a/target.h
+++ b/target.h
@@ -1,7 +1,7 @@
 #ifndef __target_H
 #define __target_H
 /*
- * Copyright (c) 1998 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-1999 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: target.h,v 1.7 1999/04/25 00:44:10 steve Exp $"
+#ident "$Id: target.h,v 1.8 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -68,7 +68,7 @@ struct target_t {
       virtual void net_assign(ostream&os, const NetAssign*);
       virtual void net_const(ostream&os, const NetConst*);
       virtual void net_esignal(ostream&os, const NetESignal*);
-      virtual void net_pevent(ostream&os, const NetPEvent*);
+      virtual void net_event(ostream&os, const NetNEvent*);
 
 	/* Output a process (called for each process) */
       virtual void start_process(ostream&os, const NetProcTop*);
@@ -121,6 +121,9 @@ extern const struct target *target_table[];
 
 /*
  * $Log: target.h,v $
+ * Revision 1.8  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.7  1999/04/25 00:44:10  steve
  *  Core handles subsignal expressions.
  *
diff --git a/targets.cc b/targets.cc
index 82b70e39a..568780184 100644
--- a/targets.cc
+++ b/targets.cc
@@ -17,19 +17,19 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: targets.cc,v 1.3 1999/01/24 01:35:36 steve Exp $"
+#ident "$Id: targets.cc,v 1.4 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include "target.h"
 
 extern const struct target tgt_null;
-extern const struct target tgt_verilog;
+//extern const struct target tgt_verilog;
 extern const struct target tgt_vvm;
 extern const struct target tgt_xnf;
 
 const struct target *target_table[] = {
       &tgt_null,
-      &tgt_verilog,
+	//&tgt_verilog,
       &tgt_vvm,
       &tgt_xnf,
       0
@@ -37,6 +37,9 @@ const struct target *target_table[] = {
 
 /*
  * $Log: targets.cc,v $
+ * Revision 1.4  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.3  1999/01/24 01:35:36  steve
  *  Support null target for generating no output.
  *
diff --git a/vvm/.cvsignore b/vvm/.cvsignore
index 7b5d7e4bc..cad51a157 100644
--- a/vvm/.cvsignore
+++ b/vvm/.cvsignore
@@ -1 +1,2 @@
 dep
+Makefile
diff --git a/vvm/vvm_gates.h b/vvm/vvm_gates.h
index a7c647674..e0c9edcd4 100644
--- a/vvm/vvm_gates.h
+++ b/vvm/vvm_gates.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vvm_gates.h,v 1.7 1999/02/15 05:52:50 steve Exp $"
+#ident "$Id: vvm_gates.h,v 1.8 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  "vvm.h"
@@ -341,20 +341,45 @@ class vvm_bufz {
       vvm_out_event::action_t output_;
 };
 
+/*
+ * Threads use the vvm_sync to wait for something to happen. This
+ * class cooperates with the vvm_pevent class that is the actual gates
+ * that receive signals. By handling the suspension and the awakening
+ * separately, I can trivially handle event OR expressions.
+ *
+ * When there is an event expression in the source, the elaborator
+ * makes NetNEvent objects, which are approximately represented by the
+ * vvm_pevent class.
+ */
+class vvm_sync {
+
+    public:
+      vvm_sync();
+
+      void wait(vvm_thread*);
+      void wakeup(vvm_simulation*sim);
+
+    private:
+      vvm_thread*hold_;
+
+    private: // not implemented
+      vvm_sync(const vvm_sync&);
+      vvm_sync& operator= (const vvm_sync&);
+};
+
 class vvm_pevent {
     public:
       enum EDGE { ANYEDGE, POSEDGE, NEGEDGE };
 
-      explicit vvm_pevent();
-      void wait(EDGE, vvm_thread*);
+      explicit vvm_pevent(vvm_sync*tgt, EDGE e);
 
       void set(vvm_simulation*sim, unsigned, vvm_bit_t val);
       vvm_bit_t get() const { return value_; }
 
     private:
+      vvm_sync*target_;
       vvm_bit_t value_;
-      vvm_thread*hold_;
-      EDGE hold_edge_;
+      EDGE edge_;
 
     private: // not implemented
       vvm_pevent(const vvm_pevent&);
@@ -363,6 +388,9 @@ class vvm_pevent {
 
 /*
  * $Log: vvm_gates.h,v $
+ * Revision 1.8  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.7  1999/02/15 05:52:50  steve
  *  Mangle that handles device instance numbers.
  *
diff --git a/vvm/vvm_pevent.cc b/vvm/vvm_pevent.cc
index f5454c5ab..50abb85bb 100644
--- a/vvm/vvm_pevent.cc
+++ b/vvm/vvm_pevent.cc
@@ -17,52 +17,49 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vvm_pevent.cc,v 1.1 1998/11/09 23:44:11 steve Exp $"
+#ident "$Id: vvm_pevent.cc,v 1.2 1999/05/01 02:57:53 steve Exp $"
 #endif
 
 # include  "vvm.h"
 # include  "vvm_gates.h"
 
-vvm_pevent::vvm_pevent()
-: value_(V0), hold_(0)
+vvm_sync::vvm_sync()
+: hold_(0)
 {
 }
 
-void vvm_pevent::wait(EDGE edge, vvm_thread*thr)
+void vvm_sync::wait(vvm_thread*thr)
 {
       assert(hold_ == 0);
       hold_ = thr;
-      hold_edge_ = edge;
+}
+
+void vvm_sync::wakeup(vvm_simulation*sim)
+{
+      vvm_thread*tmp = hold_;
+      hold_ = 0;
+      if (tmp) sim->thread_active(tmp);
+}
+
+vvm_pevent::vvm_pevent(vvm_sync*tgt, EDGE e)
+: target_(tgt), value_(V0), edge_(e)
+{
 }
 
 void vvm_pevent::set(vvm_simulation*sim, unsigned, vvm_bit_t val)
 {
-      if (hold_ == 0) {
-	    value_ = val;
-	    return;
-      }
-
       if (value_ != val) {
-	    vvm_thread*tmp;
-	    switch (hold_edge_) {
+	    switch (edge_) {
 		case ANYEDGE:
-		  tmp = hold_;
-		  hold_ = 0;
-		  sim->thread_active(tmp);
+		  target_->wakeup(sim);
 		  break;
 		case POSEDGE:
-		  if (val == V1) {
-			tmp = hold_;
-			hold_ = 0;
-			sim->thread_active(tmp);
-		  }
+		  if (val == V1)
+			target_->wakeup(sim);
 		  break;
 		case NEGEDGE:
-		  if (val == V0) {
-			tmp = hold_;
-			hold_ = 0;
-			sim->thread_active(tmp);
-		  }
+		  if (val == V0)
+			target_->wakeup(sim);
 		  break;
 	    }
 	    value_ = val;
@@ -71,6 +68,9 @@ void vvm_pevent::set(vvm_simulation*sim, unsigned, vvm_bit_t val)
 
 /*
  * $Log: vvm_pevent.cc,v $
+ * Revision 1.2  1999/05/01 02:57:53  steve
+ *  Handle much more complex event expressions.
+ *
  * Revision 1.1  1998/11/09 23:44:11  steve
  *  Add vvm library.
  *