.. a library that provides vectors/matrices in a typesafe way

Nice! But what does it have to do with accelarate :-) I mean, we could also use this somewhere in Data.Array? Else, it's re-invented all over the place - and poorly, e.g., https://github.com/jwaldmann/ersatz/blob/master/tests/Z001.hs#L51 - J.W.