I find most of this fun, I enjoy learning about the history of why things ended up like this versus that. However, I can imagine someone coming into APL and getting disorientated seeing stuff like this. And of course, these issues aren't in newer array languages such as BQN or Uiua.
Ginger Wins Here
，这一点在新收录的资料中也有详细论述
return [y is not None and xs[y] for y in presum(ys)]。新收录的资料是该领域的重要参考
const int r = 24;，推荐阅读新收录的资料获取更多信息