|| (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
&& (is_lisp_pointer(start_addr[1])
|| (fixnump(start_addr[1]))
|| (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
|| (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
&& (is_lisp_pointer(start_addr[1])
|| (fixnump(start_addr[1]))
|| (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)