The W-procedure for the construction of the W-set from a set of k-equivalence partitions is given on page 239. This is a brute force procedure that determines a distinguishing sequence for every pair...

The W-procedure for the construction of the W-set from a set of k-equivalence partitions is given on page 239. This is a brute force procedure that determines a distinguishing sequence for every pair of states. From Example 5.9, we know that two or more pairs of states might be distinguishable by the same input sequence. Rewrite the W-procedure by making use of this fact.