the usage and meaning of the term "mahāmudrā" evolved over the course of hundreds of years of indian and tibetan history, and as a result, the term may refer variously to "a ritual hand-gesture, one of a sequence of 'seals' in tantric practice, the nature of reality as emptiness, a meditation procedure focusing on the nature of mind, an innate blissful gnosis cognizing emptiness nondually, or the supreme attainment of buddhahood at the culmination of the tantric path."