Restoring confluence for functional dependencies

Functional dependencies provide for a relational specification of user-programmable type improvement connected to type class instances. On the other hand, the more recent type families (also known as type functions) equip the programmer with a functional specification for user-programmable type improvement decoupled from type class instances. Functional dependencies are supported by both GHC and Hugs, while the most recent version of GHC also supports type functions. There is an enthusiastic and lively debate which feature shall make it into the next Haskell standard, Haskell-Prime. Currently, further progress in the standardization appears to be stalled on this issue. In this paper, we attempt to rekindle the debate with new insights in type inference issues behind functional dependencies (FDs) and type functions (TFs), without taking sides.status: publishe