noIOCom)</PRE>

  <P>
    This rule implements a form of <em>black-listing</em> of components.
    When it is active, any attempt to import one of the listed components
    will immediately raise a <TT>Security</TT> exception. Note that this
    also applies to imports performed by the Alice ML <TT>import</TT>
    declaration syntax, because that ultimately is mapped to the
    <TT>Component.load</TT> function.
    We only show this for presentational purposes.
    This approach is very restrictive, because