tol::grammars

   returns the list of grammars

tol::functions <grammar> [<function>]

  returns the especification for a <function> defined in <grammar>.
  if <function> is empty returns the list of functions defined in <grammar>
  raises an error if <function> is not defined in <grammar> or <grammar> is
  not defined.

tol::variables <grammar> <variable>

  return the especification for a <variable> defined in <grammar>.
  if <variable> is empty returns the list of variables defined in <grammar>
  raise an error if <variable> is not defined in <grammar> or grammar is
  not defined.

tol::eval <expression>

  evaluate a tol <expression>