[Axiom-developer] Re: FW: data structure vs. mathematical structure

[Gabriel Dos Reis]

"Page, Bill" <address@hidden> writes:

[...excellent stuff snipped...]

| Now having thought about Stream as a type constructor solution
| of the equation X = 1 + T * X, I would like to ask you what you
| think might be the equivalent greatest fixed point solution of
| 
|   X = 1 + T * X * X
| 
| Recall first that the least fixed point solution corresponds to
| the BinaryTree type constructor.

Isn't a potentially infinite binary tree?
An effective traversal of that structure would be a breath first
traversal.  Does Axiom have a domain for that?

| I think I know the answer although I have not seen this written
| anyware else, so I want to see if you come to the same conclusion.
| :-) Ultimately it is the connection to Azcel and Jon Barwise's
| notions of non-wellfounded sets that intrigues me most. 

co-induction.

-- gaby