title: Using a tuple (i,j,k,...) to construct an intersection list_of_sets[i] & list_of_sets[j] & list_of_sets[k]
body: <p>I am searching through a tree. At each node, I need to find an intersection of some combination of sets, which are all contained in list_of_sets=[set_1,set_2,...,set_n].</p>
  
  <p>I use a tuple of indexes to keep track of which node I am in, i.e. node=[i,j,k,...]. The size of this tuple varies from 1 to 5 depending on the position in the tree.</p>
  
  <p>At any node, e.g. node=[i,j,k,l], I would like to construct such an expression:</p>
  
  <pre><code>intersection = list_of_sets[i] &amp; list_of_sets[j] &amp; list_of_sets[k] &amp; list_of_sets[l]
  </code></pre>
  
  <p>I have absolutely no clue how get started on this one. Your advice is deeply appreciated ;)</p>