   "{" token sp hide
   [ 'rhs' sp ] delay
   "}" token sp hide 
-  3array seq ;
+  3array seq [ first <ebnf-repeat0> ] action ;
 
 : 'rhs' ( -- parser )
   'repeat0'

C: <ebnf-terminal> ebnf-terminal
C: <ebnf-choice> ebnf-choice
C: <ebnf-sequence> ebnf-sequence
C: <ebnf-rule> ebnf-rule
C: <ebnf> ebnf


TUPLE: ebnf-terminal symbol ;
TUPLE: ebnf-choice options ;
TUPLE: ebnf-sequence elements ;
TUPLE: ebnf-repeat0 group ;
TUPLE: ebnf-rule symbol elements ;
TUPLE: ebnf rules ;

