title: brainf_ck not operation in a list
body: <p>I'm having a problem with the not operation (and nearly all operations) in a list. What I mean with a list is 0 i1 i2 i3 ... in-1 in 0 with a unknown n  </p>
  
  <p>In my program I'm at an unknown index in that list and I need to check if it is 0
   For the not algorithm you need a temporary value but you can only get to that value with a [&lt;] or a [>] but then you will lose the value in the list.</p>
  
  <p>reminder: the a = 0 algorithm goes like this:</p>
  
  <p><code>
      t0[-]+
      a[t0-]
      t0[
        &lt;code&gt;
      ]
  </code><br>
  The only thing I could come up with is leaving a 1 between each index but that seems extremely un-elegant. </p>
  
  <p>so my questions is : is there a better way to do this?</p>