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

      ] each
    ] { } make ,
    [ call ] , \ map , \ seq , 
  ] [ ] make ;

M: ebnf-rule ebnf-compile ( ast -- quot )

C: <ebnf-terminal> ebnf-terminal
C: <ebnf-choice> ebnf-choice
C: <ebnf-sequence> ebnf-sequence
C: <ebnf-repeat0> ebnf-repeat0
C: <ebnf-rule> ebnf-rule
C: <ebnf> ebnf

