If you are going to add a new case function somewhere in the middle of a REPL session because order matters, maybe break it with anything like write a number or something.. and then repeat the case functions with the order you wish. Now the new case functions will overwrite whatever you wrote before.. We can make a rule that the case functions should be below each other. I’ve always seen the different functions done above each other in Haskell. 

On 8 Aug 2021, at 5:10 PM, 2QdxY4RzWzUUiLuE@potatochowder.com wrote:

Because the order of cases is significant, these would be difficult to
work with in the REPL.  If, for example, I start with your three
definitions, and then decide to write a special case¹ for 2, how do I
convince Python that

   case def fib(2):
         return 1

belongs before the general case?

¹ Yeah, I know, special cases aren't special enough.  In a non-toy case
(pun intended), there could be any number of reasons to add a new case
in the middle, or to redfine/fix a case that already exists rather than
add a new case to the end.