Thanks for your reply! I think I understood some of your comment, but got very lost at the end. I don't know anything about: Kleene trees [1], "total" languages

Thanks for your reply! I think I understood some of your comment, but got very lost at the end. I don't know anything about: Kleene trees [1], "total" languages [2], general recursion vs structural recursion [3], or epsilon operators [4]. (But I've looked those up and provided some links.) I think I understood some of the first paragraph. I'll have to do some mathematics and computer science courses on Khan Academy. [1] https://en.wikipedia.org/wiki/Kleene%E2%80%93Brouwer_order https://en.wikipedia.org/wiki/Kleene%E2%80%93Brouwer_order [2] https://en.wikipedia.org/wiki/Total_functional_programming https://en.wikipedia.org/wiki/Total_functional_programming [3] https://stackoverflow.com/questions/14268749/how-does-structural-recursion-differ-from-generative-recursion https://stackoverflow.com/questions/14268749/how-does-struct... [4] https://en.wikipedia.org/wiki/Epsilon_calculus https://en.wikipedia.org/wiki/Epsilon_calculus This seems like a very advanced topic!