On flow-equivalence of R-graph shifts
  We show that Property $(A)$ of subshifts and the semigroup, that is associated to subshifts with Property (A), are invariants of flow equivalence. We show for certain $\mathcal R$-graphs that their isomorphism is implied by the flow equivalence of their $\mathcal R$-graph shifts. 
Wolfgang Krieger
math.DS