This is the root element representing a termination problem.
Versioning Information:
Version 0.4: added higher-order features (courtesy Albert Rubio and Rene Thiemann)
Version 0.32: removed the targetNamespace
Version 0.31: adds the capability to have multiple originalfilename tags;
removed the strategy=NONE.
Version 0.3: adds the /problem/metainformation/originalfilename tag.
Version 0.2: first official release
This tag shows the termination status of this problem, if known.
The reason for using sub-elements is that <yes/> can optionally
be extended by complexity bound information.
type for free variables
a higher-order symbol f with children types t1,...,tn,t has type: (t1,...,tn) -> t
for first-order terms, only funapp and var may be used
the type is the type of the bound variable
an application of a function (first term) on an argument (second term): (first second)