pan> and <span 
class="pcrr7t-">(,)</span>) and lists (such as <span 
class="pcrr7t-">[x]</span> and <span 
class="pcrr7t-">[]</span>) continues to refer to the tuples and lists defined by the
standard <span 
class="pcrr7t-">Prelude</span>; there is no way to redefine the meaning of <span 
class="pcrr7t-">[x]</span>, for example, in terms of a different
implementation of lists. On the other hand, the use of <span 
class="pcrr7t-">++</span> is not special syntax, so it refers to <span 
class="pcrr7t-">++</sp