[mmarx]

> Relatively common even outside Haskell?

It's common throughout mathematics. So common, in fact, that there's even a wikipedia article on the phenomenon[0].

“Common examples occur when speaking of compound mathematical objects. […] Similarly, one often refers to a group (G, \star) as simply G when the group operation is clear from context.”

[0] https://en.wikipedia.org/wiki/Abuse_of_notation

[spion]

Fair enough. But I don't think its surprising that it may lead to confusion when beginners study the subject.