@inproceedings { , title = {Making Functionality More General}, abstract = {The definition for the notion of a "function" is not cast in stone, but depends upon what we adopt as types in our language. With partial equivalence relations (pers) as types in a relational language, we show that the functional relations are precisely those satisfying the simple equation f = f o fu o f, where "o" and "u" are respectively the composition and converse operators for relations. This article forms part of "A calculational theory of pers as types".}, conference = {Proceedings of the 1991 Glasgow Workshop on Functional Programming}, organization = {Skye, Scotland}, publicationstatus = {Published}, url = {https://nottingham-repository.worktribe.com/output/1025037}, year = {1992}, author = {Hutton, Graham and Voermans, Ed} }