title: custom postfix notation, Apply / Function
body: <p>I would like to set up the following custom notation in Mathematica 7.</p>
  
  <p>This notation is not particularly useful in itself, so please do not suggest existing alternatives, or point out that this only saves a few keystrokes.</p>
  
  <p>I want to know if and how it may be done.</p>
  
  <hr>
  
  <p>At present, one may enter</p>
  
  <pre><code>f = #2 + #^2 / #3 &amp; @@ # &amp; ;
  
  f[ {a, b, c} ]
  
  Out[]= b + a^2 / c
  </code></pre>
  
  <p>Where the inner function <code>#^2 / #3 + #2 &amp;</code> is <code>Apply</code>'d to the first argument.</p>
  
  <hr>
  
  <p>I would like to implement the syntax</p>
  
  <pre><code>f = #2 + #^2 / #3 @@&amp; ;
  </code></pre>
  
  <p>and have it behave exactly the same.  That is, <code>@@&amp;</code> to represent a <code>Function</code> that is automatically applied to its first argument.</p>
  
  <p><em>It will need to have the same binding as the</em> <code>&amp;</code> <em>symbol.</em></p>
  
  <hr>
  
  <p>It is preferable that this is done with the <code>Notations</code> package, to whatever extent that is possible, rather than manual <code>MakeBoxes</code>, for the sake of ease in setting up similar notations, even though the use of <code>Notations</code> is more difficult to communicate via text.</p>