kitchen("flour"), kitchen("sugar"), kitchen("sugar"), kitchen("apples")
    <=> kitchen("apple cake")

kitchen("apples"), kitchen("oranges"), kitchen("cherries")
    <=> kitchen("fruit salad")

kitchen("fruit salad"), kitchen("apple cake")
    <=> kitchen("fruit cake")

start <=>
    kitchen("sugar"),
    kitchen("oranges"),
    kitchen("apples"),
    kitchen("cherries"),
    kitchen("flour"),
    kitchen("apples")