notes nextdelete although is in leafthis leaf does not have an extra keythe deletion results in node with only one keywhich is not acceptable for -tree of order if the sibling node to the immediate left or right has an extra keywe can then borrow key from the parent and move key up from this sibling in our specific casethe sibling to the right has an extra key sothe successor of (the last key in the node where the deletion occurred)is moved down from the parentand the is moved up (of coursethe is moved over so that the can be inserted in its proper place finallylet' delete this one causes lots of problems although is in leafthe leaf has no extra keysnor do the siblings to the immediate right or left in such case the leaf has to be combined with one of these two siblings this includes moving down the parent' key that was between those of these two leaves in our examplelet' combine the leaf containing with the leaf containing we also move down the lovely professional university