does not work

[geniusserg]

phd/coding/learning/haskell/typeclassopedia/ApplicativeAlternative.hs

Line 13 in ab13d13

-- (<*>) g a = fmap (uncurry $) ((**) g a)

main.hs:11:30: error:
* Couldn't match type (a -> b, a)' with a0 -> b0 -> c0'
Expected type: f (a0 -> b0 -> c0)
Actual type: f (a -> b, a)
* In the second argument of fmap', namely (() g a)'
In the expression: fmap (uncurry $) (() g a)
In an equation for ap': ap' g a = fmap (uncurry $) (() g a)
* Relevant bindings include
a :: f a (bound at main.hs:11:7)
g :: f (a -> b) (bound at main.hs:11:5)
ap' :: f (a -> b) -> f a -> f b (bound at main.hs:11:1)
|
11 | ap' g a = fmap (uncurry $) (() g a)