How does Haskell's "boobs operator" work in plain non-functional English? -

this question has answer here:

• composing function composition: how (.).(.) work? 7 answers

in answer https://stackoverflow.com/a/11006842/1065190 "owl operator" mentioned:

absoluteerror = ((.) . (.)) abs (-) 

to express absolute error function in point-free notation.

anyway, how notation work?

could you, please, explain non-functional c++ programmer?

as possible (.).(.), written (.:) sometimes, function composition when function being composed on right side has 2 missing arguments. if try use (.) directly doesn't typecheck, although it's quite tempting due idea of functional "plumbing".

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also, it's worth thinking how (.:) kind of plumbing opposite of data.function.on.

flip on :: (a -> b) -> (b -> b -> c) -> (a -> -> c) (.:)    :: (a -> b) -> (c -> d -> a) -> (c -> d -> b) 

on uses unary function transform 2 inputs of binary function. (.:) takes binary function , uses transform unary function binary function.