This article responds to the challenge set by Hugo Brandt Corstius in the May 2001 issue of Word Ways. He sought pairs of words that contained the same letters (i.e., permutations of each other), which were dual in the sense that a position occupied a vowel in one was occupied by consonant in the other. This article takes vowel to mean one of A, E, I, O, or U.
Word Ways: Vol. 34
, Article 9.
Available at: http://digitalcommons.butler.edu/wordways/vol34/iss3/9