Duck me sideways. I must have read this book, because I wrote Pascal-like compiler for 8080, by the order of Finnish Army in 1977. All I remember that I invented tail-recursion all by myself.
"The publisher of Wirth's books (Addison-Wesley) has decided to phase out all his books, but Wirth has published revised editions of his book beginning in 2004."
That is sad, but the revised editions seem to be published online.
Interesting. The article states "The compiler prints the value as a given variable changes." -- surely it means the program does, and not the compiler?
It might be more precisely stated something like "The language's semantics require that when a variable changes value, that change includes the side-effect of printing the new value."
https://photos.app.goo.gl/xeDuC7LDvo2ABMGo9
Me myself find the remarkable, because I could not get to the "Digital Science"-faculty because of bad scores and inappropriate hairdo.
That is sad, but the revised editions seem to be published online.
PL/0, PS/2, CP/M, etc.
And then Gary Kildall also seemed to like it with CP/M and PL/M, but those were after IBM had used it and I'd guess Gary was just copying IBM.
Between just those two influences you cover a huge portion of the mainframe and micro computer worlds during the 60s-80s