--- a/absyntax/absyntax.def	Sat Nov 17 09:44:14 2007 +0100
+++ b/absyntax/absyntax.def	Sat Nov 17 10:08:38 2007 +0100
@@ -1,5 +1,5 @@
 /*
- * (c) 2003 Mario de Sousa
+ * (c) 2003-2007 Mario de Sousa
  *
  * Offered to the public under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2 of the
@@ -555,31 +555,61 @@
 /* B.1.6  Sequential function chart elements */
 /*********************************************/
 
+/* | sequential_function_chart sfc_network */
 SYM_LIST(sequential_function_chart_c)
 
+/* initial_step {step | transition | action} */
 SYM_LIST(sfc_network_c)
 
+/* INITIAL_STEP step_name ':' action_association_list END_STEP */
 SYM_REF2(initial_step_c, step_name, action_association_list)
 
+/* | action_association_list action_association ';' */
 SYM_LIST(action_association_list_c)
+
+/* STEP step_name ':' action_association_list END_STEP */
 SYM_REF2(step_c, step_name, action_association_list)
+
+/* action_name '(' action_qualifier indicator_name_list ')' */
+/* action_qualifier -> may be NULL ! */
 SYM_REF3(action_association_c, action_name, action_qualifier, indicator_name_list)
 
+/* N | R | S | P */
 SYM_TOKEN(qualifier_c)
+
+/* L | D | SD | DS | SL */
 SYM_TOKEN(timed_qualifier_c)
 
+/* | indicator_name_list ',' indicator_name */
 SYM_LIST(indicator_name_list_c)
 
+/* qualifier | timed_qualifier ',' action_time */
+/* action_time -> may be NULL ! */
 SYM_REF2(action_qualifier_c, action_qualifier, action_time)
 
+/* TRANSITION [transition_name] ['(' PRIORITY ASSIGN integer ')'] 
+ *   FROM steps TO steps 
+ *   transition_condition 
+ * END_TRANSITION
+*/
+/* transition_name -> may be NULL ! */
+/* integer -> may be NULL ! */
 SYM_REF5(transition_c, transition_name, integer, from_steps, to_steps, transition_condition)
 
+/* ':' eol_list simple_instr_list | ASSIGN expression ';' */
+/* transition_condition_il -> may be NULL ! */
+/* transition_condition_st -> may be NULL ! */
 SYM_REF2(transition_condition_c, transition_condition_il, transition_condition_st)
 
+/* step_name | '(' step_name_list ')' */
+/* step_name      -> may be NULL ! */
+/* step_name_list -> may be NULL ! */
 SYM_REF2(steps_c, step_name, step_name_list)
 
+/* | step_name_list ',' step_name */
 SYM_LIST(step_name_list_c)
 
+/* ACTION action_name ':' function_block_body END_ACTION */
 SYM_REF2(action_c, action_name, function_block_body)
 
 /********************************/