n be
exponentially slower for models with many variables
(e.g., > 6 binary hidden nodes).

<p>
The use of both
<tt>jtree_dbn_inf_engine</tt>
and
<tt>hmm_inf_engine</tt>
is deprecated.
A better approach is to construct a smoother engine out of lower-level
engines, which implement forward/backward operators.
You can create these engines  as follows.
<pre>
engine = smoother_engine(hmm_2TBN_inf_engine(bnet));
or
engine = smoother_engine(jtree_2TBN_inf_engine(bnet));
</pre>
You then call them in the usual way:
<