When is a function a fold or an unfold?

Gibbons, Jeremy; Hutton, Graham; Altenkirch, Thorsten

Abstract

We give a necessary and sufficient condition for when a set-theoretic function can be written using the recursion operator fold, and a dual condition for the recursion operator unfold. The conditions are simple, practically useful, and generic in the underlying datatype.

Citation

Gibbons, J., Hutton, G., & Altenkirch, T. When is a function a fold or an unfold?. Presented at Workshop on Coalgebraic Methods in Computer Science (4th)

• Conference Name: Workshop on Coalgebraic Methods in Computer Science (4th)
• End Date: Apr 7, 2001
• Publication Date: May 1, 2001
• Deposit Date: Feb 26, 2015
• Publicly Available Date: Feb 26, 2015
• Peer Reviewed: Peer Reviewed
• Volume: 44.1
• Series Title: Electronic Notes in Theoretical Computer Science
• Public URL: https://nottingham-repository.worktribe.com/output/1023065
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S157106610480906X
• Additional Information: Published in Electronic Notes in Theoretical Computer Science, 44(1), May 2001, 146-160, doi: 10.1016/S1571-0661(04)80906-X