“…This, however, is not a deal breaker for majority-based error correction (both classical and quantum) as long as the erroneously classified instances are rare with respect to the noise channel in question. Motivated by applications for classical error correction, there evolved a vivid field concerned with the construction of approximate density classifiers (e.g., [53,35,54,55,56]) and extensions capable of performing density classification exactly (e.g., [57,58,59,60]), see [42] for a review. This is how we address the problem of finding a local decoder for the MCQC: Lemma 1 allows us to filter the literature of one-dimensional binary CAs for self-dual density classifiers; rewritten in syndrome-delta representation, these could be directly applied as potential Majorana chain decoders.…”