title: I do not understand these LESS function code (if, boolean)
body: <p>I did not understand these codes LESS! thank you for helping me</p>
  
  <pre><code>@bg: black;
  @bg-light: boolean(luma(@bg) &gt; 50%);
  
  div {
      background: @bg; 
      color: if(@bg-light, black, white);
  }
  </code></pre>
  
  <p>and this code :</p>
  
  <pre><code>@some: foo;
  
  div {
      margin: if((2 &gt; 1), 0, 3px);
      color:  if((iscolor(@some)), darken(@some, 10%), black);
  }
  </code></pre>