Use of function application operator in Haskell -

what following expression means in haskell?

($ 3)

ghci shows following type

($ 3) :: num => (a -> b) -> b.

($ 3) section, , equivalent \f -> f 3, takes function argument , applies 3.

if considered 3 integer, have type of f int -> b (for b), type of ($ 3) (int -> b) -> b.

things in haskell bit more complex, since 3 can of numeric type, don't need f :: int -> b, it's enough if f :: -> b a numeric type.

hence ($ 3) :: num => (a -> b) -> b.

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