anchor.diff:  clauses -> clause clauses : ['$1'|'$2'].
   clauses -> clause : ['$1'].
   
  -clause -> when expr separator statements : {clause, line('$1'), '$2', '$4'}.
  +clause -> when expr separator expr_list : {clause, line('$1'), '$2', '$4'}.
   
   %% Case expressions
   case_expr -> 'case' expr separator clauses 'end': {'case', line('$1'), '$2', '$4'}.
  
positive.code:   end;
  extract_fragment(Continuation, [Char|String], Line) ->
    {more, Continuation2} = reia_scan:tokens(Continuation, [Char], Line),
    extract_fragment(Continuation2, String, Line).
negative.code: 
  Nonterminals
    grammar
    expr_list
    separators
    separator
    inline_statements
  