It is a bit tricky. The point I made in my post is that there is (or at least should) a difference between a recursive procedure and a recursive process. The term recursive procedure only refers to the fact that the procedure definition refers to itself. This doesn't necessarily result in a recursive process.

The difference between the processes is whether the process is characterized by linear growth because of delayed stack operations (recursive) or whether the process is static because the state of the program is defined entirely by state variables.

fi_helper() is indeed a recursive procedure, but written in a language that supports tail-recursion (like LISP), it doesn't generate a recursive process. My question was whether it would generate a recursive process in Perl.