title: R equivalent of python "_"?
body: <p>Python has an identifier <code>_</code> that allows for storing the result of the <a href="http://docs.python.org/reference/lexical_analysis.html#reserved-classes-of-identifiers">last evaluation</a> which makes it great for speeding up data exploration and introspection.</p>
  
  <pre><code>In [1]: 43 * 2
  Out[1]: 86
  
  In [2]: _ + 1
  Out[2]: 87
  </code></pre>
  
  <p>Is there a similar command in R?</p>