Vol. 26, No. 2/3, Learning Mathematics: Constructivist and Interactionist Theories of Mathematical Development (Mar., 1994), pp. 135-164 (30 pages) Conventional treatments of functions start by ...

As in [Entire slice regular functions, Springer, 2016] we define the ∗-exponential of a slice-regular function, which can be seen as a generalization of the complex exponential to quaternions.