Flow-equivalence conjecture for irreducible shifts of finite type and renewal systems

An irreducible shift of finite type (SFT) is an irreducible symbolic dynamical system defined by finitely many forbidden words, and a renewal system is a shift generated by concatenations of a finite collection of words. Flow-equivalence conjecture. Every irreducible SFT is flow equivalent to a renewal system. This is presented as an alternative conjectural resolution of Adler's question, alongside the conjecture that some irreducible SFT is not conjugate to any renewal system; the source gives no resolution.