title: Least Squares with two inequality constraints
body: <p>I have a least square problem with two different inequality problems. i can not use NNLS because its just solve least square problem with equality and inequality problems or just one inequality constraint. 
  can i use NNLS  or any other algorithm or R package  that i can solve this least square problem?</p>
  
  <pre><code>    min|| Ax-b||^2    x = c(c, d, f) is a vector
      x &gt;= 0 
      c + d * x + f * x &gt;= 0
  </code></pre>