floating-point constants (which are clearly not NaNs); however, if
  performance really does matter, you will probably use a good compiler which
  knows how to inline functions and all these annoying little tests will
  magically disappear (if not, it is time to upgrade your compiler).</p>

  <h3>Manipulating wide intervals</h3>

  <p>You may want to use the library on intervals with imprecise bounds or on
  inexact numbers. In particular, it may be an existing algorithm that you
  want to rewrite and simpl