diff --git a/tool/playground/T.g b/tool/playground/T.g
index f6fa568c9..af669d4f7 100644
--- a/tool/playground/T.g
+++ b/tool/playground/T.g
@@ -1,24 +1,9 @@
 grammar T;
-@members {
-public static class LeafListener extends TBaseListener {
-    public void exitCall(TParser.CallContext ctx) {
-        System.out.printf("%s %s",ctx.e().start.getText(),
-                          ctx.eList());
-    }
-  }    public void exitInt(TParser.IntContext ctx) {
-      System.out.println(ctx.INT().getText());
-    }
-}
-s
-@init {setBuildParseTree(true);}
-@after {  System.out.println($r.ctx.toStringTree(this));  ParseTreeWalker walker = new ParseTreeWalker();
-  walker.walk(new LeafListener(), $r.ctx);}
-  : r=e ;
-e : e '(' eList ')' -> Call
-  | INT             -> Int
-  ;     
-eList : e (',' e)* ;
-MULT: '*' ;
-ADD : '+' ;
-INT : [0-9]+ ;
-WS : [ \t\n]+ -> skip ;
+s : a a a;
+a : {false}? ID 
+  | {true}?  ID
+  | INT       
+  ;
+ID : 'a'..'z'+ ;
+INT : '0'..'9'+;
+WS : (' '|'\n') {skip();} ;