And: print "Hello, World!" gives no knowledge how to put text on the screen. Con...

And:

  print "Hello, World!"

gives no knowledge how to put text on the screen. Conversely, there's no reason a standard library couldn't include:

  fn (*) :: Num -> Num -> Num
  fn (a * b) = [machine code goes here]
  un (_ * d) n = n/d
  un (d * _) n = n/d
  un (_ * _) n = sqrt(n)

or similar.