further on rotation in the example on my other post i needed to rotate the 20 to the left. so the 15 right pointer has to point at the 30 so i need someway of accessing the 15 to set its right pointer to 30.
if 20 stored its parent pointer it is then "just" a case of making it point to the 30.
here is what i am basing my theory on
YouTube 4,00 is where it starts