**Exercise 4.2:**

* Suppose you have a relation v(N,W) that is true if there is a vowel (one of: a, e, i, o, u) as the N-th letter of word W. For example, v(2,cat) is true because there is a vowel (“a”) as the second letter of the word “cat”;v (3,cat) is false, because the third letter of “cat” is “t”, which is not a vowel; and v(5,cat) is also false because there is no fifth letter in “cat”.

* Suppose the domain of N is {1,3,5} and the domain of W is {added, blue, fever, green, stare}.

– Is the arc ⟨N,v⟩ arc consistent? If so, explain why. If not, show what element(s) can be removed from a domain to make it arc consistent.

– Is the arc ⟨W,v⟩ arc consistent? If so, explain why. If not, show what element(s) can be removed from a domain to make it arc consistent.

( Exercise 4.2 s Reference link is: http://artint.info/html/ArtInt_99.html )