Trace the topological sort algorithm (4.3.1) for the pancake recipe in Example 1 by starting with the source 1. There are several possible answers because any source can be output by the algorithm.

Example 1 A Pancake Recipe Suppose we have the following recipe for making pancakes. . Mix the dry ingredients (our, sugar, baking powder] in a bowl. . Mix the wet ingredients (milk, eggs]I in a bowl. . Mix the wet and dry ingredients together. . Oil the pan. (It's an old pan.) . Heat the pan. . Make a test pancake and ther it away. . Make pancakes. 1 2V3)*5)*7 4)5/ Figure 4.3.1 A pancake recipe. Steps 1 through T indicate an ordering for the steps of the recipe. But the steps could also he done in some other order. To help us discover some other orders, let's dene a relation R on the seven steps of the pancake recipe as follows: i Rj means that Step i must he done before Step 1