Indian Mathematics c8.11

c8.11

(generally abbreviated to *yā* and *kā*) in one system suggests the possibility of a mixed origin. It is possible that the former is connected with Diophantus' definition of the unknown quantity, *plēthos monádon aoriston*, *i.e.*, ‘an undefined (or unlimited) number of units.’ To pass from ‘an unlimited number’ to ‘as many as’ requires little imagination. Diophantus had only one symbol for the unknown and if the use of *yāvat tāvat* were of Diophantine origin the Indians would have had to look elsewhere for terms for the other unknowns. With reference to the origin of the use of colours for this purpose we may point out that the very early Chinese used calculating pieces of two colours to represent positive and negative numbers.