This is beautiful, genuinely (the SVGs are lovely bits of artwork) and it's a fun puzzle to read, and I've shared with friends that like esolangs, including your book (good luck on publishing!).
In the "Data Strands" -> "Value Strands" section, you describe it as "Value strands (and other data strands), begin with a hook that points up (as in the third strand below) or to the left (as in the first two)" for the following example:
1 ╵╰──╮╭──╯╶╮
2 ─┘└─ └─╮
3
5 ╷
but the way I was parsing it was that the hook is '╰' or '╯', in which case both of those are hooks pointing up? It looks like a fairly innocuous typo, but I'm never sure with an esolang so wanted to ask. Yes, that's a typo: the first two strands have hooks pointing up, the third to the left.
I forgot to mention that you can run the interpreter with -p to convert the program to pseudo-code. This makes it much easier to tweak the examples and experiment. I'll add that to the readme, along with more pseudo-code for the example programs.
And thanks so much!! Very excited to publish (Sept 2025).
Thanks, as I said, easy to fool yourself into thinking you're wrong when esolangs are involved.
The CLI tool is fantastic. I never thought that I'd see an esolang where "ergonomics of using it" was something the author would work on. I'll play around with that some more later, thanks again!