compose andThen

scala> def subtractOne(n: Int) = n - 1
subtractOne: (n:Int)Int

scala> def double(n: Int) = n * 2
double: (n:Int)Int

scala> def doubleAndSubtractOne = subtractOne _ compose double _
doubleAndSubtractOne: Int => Int

scala> val x = doubleAndSubtractOne(3)
x: Int = 5
// same as -> subtractOne(double(n))

scala> def subtractOneAndDouble = subtractOne _ andThen double _
subtractOneAndDouble: Int => Int

scala> val y = subtractOneAndDouble(3)
y: Int = 4
// same as -> double(subtractOne(n))