[Haskell-beginners] A very counterintuitive behaviour of Haskell

[Renzo Orsini]

In studying Haskell, I produced the following output from GHC:

xxx-3:~ xxx$ GHCi
GHCi, version 6.12.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Prelude> let f 7 = "ok"
Prelude> let f x = "no"
Prelude> f 3
"no"
Prelude> f 7
"no"


I suppose it is correct. However, for someone who is interested in the language, it seems very counterintuitive... Somebody would be so kind to explain to a neophyte this "feature" of the language?

Thank you very much.

Renzo