code: func Add(t *Pot, val Val, pof Pof) (*Pot, int, bool) {
  	return add(t, val, pof)
  }
docs: // Add inserts a new value into the Pot and
  // returns the proximity order of v and a boolean
  // indicating if the item was found
  // Add called on (t, v) returns a new Pot that contains all the elements of t
  // plus the value v, using the applicative add
  // the second return value is the proximity order of the inserted element
  // the third is boolean indicating if the item was found