No, no, plai-typed is great. I meant that PLAI book initially used a dynamically typed language (and I guess it is preserved in the printed edition), but you switched to plai-typed afterwards, and I believe you'll switch to full static typed Pyret for this book as well, when it becomes ready :)

("shameless plug": Actually, it was me who notified you about the plai-typed effort and you further developed it, during your online PLAI class at Brown ;))

Agree about a typed discipline, but I meant specifically static typing for the implementation (host) language.

As for preferences, yes, actually Noel has a point - learning debugging type errors in a dynamic languages is a skill useful in a "real world" (unfortunately :))