Abstract

Let X0, X be mixing one-sided subshifts of finite type such that X0 X. We show a necessary and sufficient condition for the existence of mixing Markov shifts Y0, Y, Y0 Y, and a conjugacy it : Y ? X with ?(Y0) = X0, such that the sets of letters appearing in both systems are the same, more precisely, L1(Y0) = L1(Y). © 1998 American Mathematical Society.