type __ghdl_index_type is unsigned (32);
type __ghdl_bool_type is boolean {false, true};

public function main (a : __ghdl_index_type) return __ghdl_index_type
declare
begin
  case __ghdl_bool_type'(a > 10) is
    when __ghdl_bool_type'[true] =>
    when __ghdl_bool_type'[false] =>
      return 1;
  end case;
  return 4;
end;