Now, to actually order the different fragments together to find the correct order of the fragments, we have to use two or more different proteolytic enzymes to produce different sets of fragments. And then we can use the overlapping regions of those fragments in the two different sets to basically determine what that sequence is. Now, to see another example of what we mean, let's take a look at the following example. So, suppose you purify protein, and that protein consists of seven amino acids. Now, your goal is to basically find what the exact sequence of amino acids is in that given protein. And what you do is you expose the protein to two different proteolytic agents, thereby producing two sets of different fragments.