⁠-tuple. When the index set is the set of all pure quantities an indexed relatives is termed a sequence.⁠ as well as the set of all actual numbers hold the very same cardinality, a bijection currently being furnished by the operate ⁠ x ↦ tan ⁡ ( π x / two ) displaystyle xmapsto tan(pi x/2) Business Disruption Disregard for set guidelines