User blog comment:Mh314159/Natural number recursion - first 4 rule sets/@comment-35470197-20191019143654/@comment-39585023-20191019223620

Changing the zero replacement rules the way I did was clearly a mistake and I have gone back to the better, original definition. Now it is clearly stated that it applies only to expressions of a certain type and the functional power is omitted. I also tried to include additional specific statements about other expressions.