The sequence equivalence problem for primitive D0L systems

摘要

The D0L sequence equivalence problem consists of deciding, given two morphisms g:X⁎→X⁎, h:X⁎→X⁎ and a word w∈X⁎, whether or not gi(w)=hi(w) for all i⩾0. We show that in case of primitive morphisms, to decide the D0L sequence equivalence problem, it suffices to consider the terms of the sequences with i<7n3nlogn, where n is the cardinality of X. A smaller bound is obtained for primitive looping morphisms.