anchor.diff:      | TOKEN_LBRACK
       | TOKEN_LBRACE_COLON_PATTERN
       | TOKEN_LBRACE
  +    | TOKEN_LAYERED_EFFECT
       | TOKEN_LARROW
       | TOKEN_IRREDUCIBLE
       | TOKEN_INT8
  
positive.code:     | NONTERM_separated_nonempty_list_DISJUNCTION_conjunctivePat_
      | NONTERM_separated_nonempty_list_SEMICOLON_appTerm_
      | NONTERM_separated_nonempty_list_SEMICOLON_effectDecl_
      | NONTERM_separated_nonempty_list_SEMICOLON_fieldPattern_
      | NONTERM_separated_nonempty_list_SEMICOLON_lidentOrOperator_
      | NONTERM_separated_nonempty_list_SEMICOLON_tuplePattern_
      | NONTERM_inputFragment
  
negative.code:     | NONTERM_flag
      | NONTERM_range
      | NONTERM_some_fsTypeArgs_
      | NONTERM_right_flexible_list_SEMICOLON_fieldPattern_
      | NONTERM_right_flexible_list_SEMICOLON_noSeqTerm_
      | NONTERM_right_flexible_list_SEMICOLON_recordFieldDecl_
      | NONTERM_right_flexible_list_SEMICOLON_simpleDef_
      | NONTERM_right_flexible_nonempty_list_SEMICOLON_fieldPattern_
      | NONTERM_right_flexible_nonempty_list_SEMICOLON_recordFieldDecl_
      | NONTERM_right_flexible_nonempty_list_SEMICOLON_simpleDef_
      | NONTERM_reverse_left_flexible_list_BAR___anonymous_7_
  