[Haskell-beginners] Pattern matching over functions

[Ken KAWAMOTO]

Thank you all. Reading through this thread from the top again, I got it finally.
I was stupid and missing the context of the original question.

*if* we have that map function that can only incompletely distinguish
functions, then by using the map function we could tell "f" from "id
f", breaking referential transparency. (assuming it couldn't detect
the equality between "f" and "id f")

Regards,
Ken