>The ancients may have understood negative numbers, but IIRC the concept of zero (additive identity) wasn't understood until Arabic Numbers / Algebra. So "zero"

>The ancients may have understood negative numbers, but IIRC the concept of zero (additive identity) wasn't understood until Arabic Numbers / Algebra. So "zero" isn't real, at least not to the Romans or Greeks. The idea of the point as a pseudo-algebraic value was very much prominent in euclids elements. The symbol came later, but of course the concept was very much established. It is preposterous to attribute to a civilization which, in Archimedes, discovered calculus, that they did not understand the concept of zero. They just thought far more geometrically than most people are used to. Also by "real" he means cauchy sequences of rationals, or some equivalent definition.