ASSERT (offset + sizeof_word <= sizeof(unsigned_N));
ASSERT (word < (sizeof (unsigned_N) / sizeof_word));
ASSERT ((sizeof (unsigned_N) % sizeof_word) == 0);
ASSERT (offset + sizeof_word <= sizeof(unsigned_N));
ASSERT (word < (sizeof (unsigned_N) / sizeof_word));
ASSERT ((sizeof (unsigned_N) % sizeof_word) == 0);