Pretty sure that's a mistake in the article. We're supposed to be in 2051 looking back at a sample of code written in 2021.

...and mutable values by default.

... and single character ASCII non-UTF-8 variable names.

... and no types. So if a and b are strings in a "mostly string-ish language" then the value of b is "101" halfway thru and "111" at the end, right?

(I'd cut them a break if they used a single expressive and meaningful kanji even ifs only one glyph, although I'm struggling to think of a kanji that implies type and a compiler smart enough to understand the type embedded in the kanji... although it could happen)