dual number

This is particularly the case with regard to the pronouns of the dual number, which form one of the peculiarities of the language.

If f(x) is a polynomial or a power series then its derivative can be obtained “automatically” using dual numbers as follows: f'(x)=f(x+𝜀)-f(x)/𝜀 where f(x+𝜀) should be expanded using the algebra of dual numbers. The role of the ε is therein similar to that of an infinitesimal.