论文信息 - Iterated Substitutions and Locally Catanative Systems: A Decidability Result in the Binary Case

Iterated Substitutions and Locally Catanative Systems: A Decidability Result in the Binary Case

Given a substitution h over a binary alphabet (a,b) and the infinite sequence a, h(a), h2(a),..., hn(a),..., we prove that for some m>0 the m-th term hm(a) of the sequence is an arbitrary product of the previous terms, if and only if it is already the case for m=2. This settles in a particular case the decidability of the local catenativity of the DOL-sequence, a longstanding open problem posed some fifteen years ago.

Christian Choffrut

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