Null -> Nil; added BEGIN section

test/m2data.in

@@ -6,6 +6,7 @@ PROCEDURE AppendIntList( a, b : IntList ) : IntList;
 }
 
 GLOBAL {
+FROM BIO IMPORT PutLn;
 
 @@
 PROCEDURE AppendIntList( a, b : IntList ) : IntList;
@@ -14,6 +15,10 @@ BEGIN
 END AppendIntList;
 }
 
+BEGIN {
+	PutLn( "initialization of m2data complete!" );
+}
+
 TYPE {
 First = A | B | C | D | E;
 Second = A( int aa );
@@ -22,8 +27,8 @@ Fourth = A | B | C( int cc ) | D | E;
 Fifth = A | B | C( int cc ) | D( string dd ) | E;
 Sixth = A( int aa ) | B | C | D | E;
 
-IntList = Null "null" | Cons( int first, IntList next ) 1 " , " 2;
-ILList  = Null "null" | Cons( IntList first, ILList next ) "[ " 1 " ] , " 2;
+IntList = Nil "nil" | Cons( int first, IntList next ) 1 " , " 2;
+ILList  = Nil "nil" | Cons( IntList first, ILList next ) "[ " 1 " ] , " 2;
 IdTree  = Leaf( string id, IntList l ) "leaf( '" 1 "', [ " 2 " ] )"
 	| Node( IdTree left, IdTree right ) "node( " 1 " , " 2 " )";
 }