The details of lexical scope where defined in Algol 60 (1960), nearly 2 decades before Rabbit (1978).
People did know how to implement things back then, and TeX is a great example of that. It is just our definitions have changed over the years of what we consider better.
People did know how to implement things back then, and TeX is a great example of that. It is just our definitions have changed over the years of what we consider better.