? incorporates a cardinality smaller sized than or equal on the cardinality of A different established ? T displaystyle T ? along with the list of all genuine figures hold the identical cardinality, a bijection getting supplied by the operate ? x ? tan ? ( ? x / two ) displaystyle xmapsto tan(pi x/two) D?ch trong m?i ?ng d?ng B?t k? b?n ?ang dùng