Sheehan Olver

I don’t think it actually solves a problem. I’m inclined to change it to ```Julia copy(d::Domain) = d ```

You are certainly right, at least in theory. In practice, I can’t think of a case where it matters. But for the sake of not intentionally writing “bad“ code I’ll...

`angle` refers to the argument in the complex plane, and so the current definition is correct as the argument does not change if we perturb a real number by a...

Your proposed angle could be implemented as a separate function `DualNumbers.dualangle`. Overriding `Base.angle` would be confusing in the context of complex numbers. This confusion is the reason that `Base.real` overrides...

How is sqrtm defined at [0 1; 0 0]? The usual definitions of matrix functions (Taylor series, Cauchy integral formula) don't seem to apply when the spectrum touches a singularity....

Ok I guess that's the analytic continuation version.

Just use a `Complex{

What could be added is support for `derivative(f, im)` but that doesn't require a redesign of `Dual`.

Changing `Dual`s supertype to `Number` will be incredibly disruptive and break a lot of code. I think there is no chance a PR doing this will be merged so I...

` Exclude ` doesn’t have any mathematical meaning that I can think of...