ginal orderings. For
instance,</p><pre>Index[<span class="std">Int</span>](<span class="num">1</span>,<span class="num">2</span>) stack Index[<span class="std">Char</span>](<span class="lit">'a'</span>,<span class="lit">'b'</span>)</pre><p>results in</p><pre>Index[(<span class="std">Int</span>, <span class="std">Char</span>)]((<span class="num">1</span>,<span class="lit">'a'</span>), (<span class="num">1</span>,<span class="lit">'b'</span>), (<span class="num">2</span>,<span class="lit">'a'</span>), (<span 