In Example 12.8, the query ?- classmates(jane_doe, X) will succeed three times: twice with X = jane_doe and once with X = ajit_chandra. Show how to modify the classmates(X, Y) rule so that a student...

In Example 12.8, the query ?- classmates(jane_doe, X) will succeed three times: twice with X = jane_doe and once with X = ajit_chandra. Show how to modify the classmates(X, Y) rule so that a student is not considered a classmate of himself or herself. Modify Example 12.17 so that the goal path(X, Y), for arbitrary alreadyinstantiated X and Y, will succeed no more than once, even if there are multiple paths from X to Y.