THEM: i'll give you two balls for one hat  YOU: you can have 2 balls if i can have 2 books and 1 hat  THEM: no way.  YOU: you can have 1 hat if i can have everything else  THEM: i want one book and one hat and you get 1 book and all the balls  YOU: no deal  THEM: no deal  YOU: no deal  THEM: ok you can have 2 books and 1 hat  YOU: okay deal  THEM: deal.