My only knowledge of `ApproxFun`

is from the brief documentation which states that it "is a package for approximating functions. It is in a similar vein to the Matlab package `Chebfun`

". I have dug up the `ChebFun`

guide, as well as the books:

- Trefethen, L.N. and Birkisson, Á and Driscoll, T.A. (2017).
*Exploring ODEs*, SIAM. - Trefethen, L.N. (2020).
*Approximation Theory and Approximation Practice. Extended Edition*, SIAM.

Questions:

- Is
`ApproxFun`

implemented in Julia, or is it linked to some Python or similar code? - Does
`ApproxFun`

support the possibilities of`ChebFun`

as described in Trefethen et al. (2017) and/or Trefethen (2017)? Or a subset of these? Or a superset of these?

Thanks for answers.