title: R combinating vector
body: <p>Suppose im have vector</p>
  
  <pre><code>c("A","B","C")
  </code></pre>
  
  <p>im need get list or vector combinating all variables( order is not important )</p>
  
  <pre><code>"A,B"
  "A,C"
  "B,C"
  "A,B,C"
  </code></pre>