  Sequentiable structures are a subclass of monoids that generalise the free
monoids and the monoid of non-negative real numbers with addition. In this
paper we consider functions $f:\Sigma^*\rightarrow {\cal M}$ and define the
Myhill-Nerode relation for these functions. We prove that a function of finite
index, $n$, can be represented with a subsequential transducer with $n$ states.
