I was going to ask if there was any plan to make a version of the for loop with controllable skip, but when I searched to see if it was already on the forum, I found this and learned I could do it myself!
And also
OK, now I feel less excited, but good to know that resource is there. Interesting how that one set up the positive/negative step with a test given to (call)
Yeah, that's why I wrote the original BYOB tools-sprite FOR to use a step of ±1 depending on which of START and END is bigger, just so I could show off using procedures as data! :~) But I also like to show off how the version that assumes a step size of 1 (as shown on the front cover of the manual!) is so ridiculously simple as to be instantly understood even by someone who's never seen procedure as data before.