Automorphisms of subword-posets

In this paper the automorphism group of two posets, D k,n and Bm,n is determined. D k,n is the poset of DNA strands of length at most n, built up with k complement pairs of letters, and partially ordered by the subsequence relation. Bm,n is the set of all subsequences of the word um,n = a1...an defined over the alphabet {0, 1,..., (m−1)}, where ai ≡ i (mod m). The automorphism group of Bm,n was known already (see Burosch et al. [1]), here a short proof is presented as an illustration of the method used in the first part.