Jeremy Tan Jie Rui

HWB colour space + CSS Level 4 syntax

5

This will fix #61. I made a notebook with a picker for this space [here](https://observablehq.com/@parcly-taxel/the-hwb-colour-model).

Byrd & Friedman 113.02 says that the following identities should be always true, where `n` is an integer: * `ellipe(n*pi + phi, m) = 2*n*ellipe(m) + ellipe(phi, m)` * `ellipf(n*pi...

Series methods for zeta and polygamma

4

#### References to other Issues or PRs Fixes #23635. #### Brief description of what is fixed or changed This PR completes the implementation of normal and asymptotic series for the...

This PR is like sympy/sympy#23984, but for Arb. It implements the generalised Bernoulli function from @PeterLuschny's "[An introduction to the Bernoulli function](https://arxiv.org/abs/2009.06743)": $$B(s,a)=\begin{cases}1&s=0\\\\-s\zeta(1-s,a)&s\ne0\end{cases}$$ as well as the ordinary version $B(s)=B(s,1)$....

This issue was discovered during fuzz-testing for the generalised Euler function [here](https://github.com/sympy/sympy/pull/23926#issuecomment-1238519022). @oscarbenjamin said: > It seems that this hangs: > > ```python > euler(-1, -1+I).evalf() > ``` I quickly...

This pull request is part of the project at https://github.com/sympy/sympy/pull/23926 and also fixes #604.