title: xmodmap: how to map Alt_L+w to arrowUp
body: <p>I've been playing with this for hours and I can't figure it out.</p>
  
  <p>I would like to map the WASD to the arrows but only when pressing ALT_L + (wasd).</p>
  
  <p>I used xmodmap</p>
  
  <p>Here is what I have so far.</p>
  
  <pre><code>keycode 25 = w W KP_Up ! also tried Up....
  clear mod1 
  add mod1 = Alt_L Meta_L
  </code></pre>
  
  <p>The only time I managed to make it work is with the Shift_L
  e.g
  keycode 25 = w Up
  works fine but I lose "W"</p>
  
  <p>Also tried using the Super_L in mod3 (and failed) ... but I really want the Alt_L.</p>
  
  <p>Finally, the Up seems to overwrite the w key in some cases. If I use something else (e.g <code>less</code>), it works.</p>
  
  <p>Please advise.</p>
  
  <p>Thanks,</p>
  
  <p>-hbt</p>
  
  <p>PS: Perhaps you could clarify modifiers for me? I don't seem to get it</p>