tadgavāśvādayaḥ śabdā nityasambandhayoginaḥ / saṅketasavyapekṣatvānnaiva gāvyādiśabdavat //
Therefore, words such as "go" [cow], "aśva" [horse] and others cannot have eternal relations, because they depend upon convention, just like words such as "gāvī" and others.