Injective type families

Richard Eisenberg eir at
Mon Jan 11 16:35:05 UTC 2016

I'm joining this conversation late, but I favor TypeFamilyDependencies over InjectiveTypeFamilies. We use the annotations for things other than injectivity! For example,

> type family Plus a b = r | r a -> b, r b -> a

is not injective under any common understanding of the word. And the argument-to-argument dependencies Simon has been musing about are even further from the meaning of "injective".


On Jan 8, 2016, at 6:43 AM, Jan Stolarek <jan.stolarek at> wrote:

>> Is "InjectiveTypeFamilies" a good name for this?  Or "TypeFamilyDependencies"?  Or what?
> My vote for "InjectiveTypeFamilies".
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