  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.
