sentences:  Kamil Zvelebil, even while acknowledging the fragility of the synchronism, called it the "sheet anchor" of the dating of Tamil literature.The synchronism however, involves numerous conjectures and has been dismissed by Gananath Obeyesekere in his "The Cult of the Goddess Pattini" (1984) as ahistorical and invalid.From a mention in the "Silappatikaram", the Sinhalese king of Lanka, Gajabahu is taken to be a contemporary of the Chera king Senguttuvan.