Computing Non-Repetitive Sequences with a Computable Lefthanded Local Lemma

The lefthanded Lov\'asz local lemma (LLLL) is a generalization of the Lov\'asz local lemma (LLL), a powerful technique from the probabilistic method. We prove a computable version of the LLLL and use it to effectivize a collection of results on the existence of certain types of non-repetitive sequences via the LLL and LLLL. This represents the first constructive proof of these results.