Grinberg defined Nyldon words as those which cannot be factorized into a sequence of lexicographically nondecreasing smaller words. He was inspired by Lyndon words, the same way except with "nondecreasing" replaced "nonincreasing." Charlier, Philibert, and Stipulanti proved that, like any word has unique factorization They also show that form right Lazard set, equivalently, Hall set. In this pa...