title: how does cobegin work?
body: <p>I don't know how do concurrent processes work? for example what is the output of this program maybe occur?</p>
  
  <pre><code>void main()
  {
   a = 0;
   cobegin { p(); p(); }
  }
  const int n = 50;
  int a;
  int i;
  void P()
  {
  for ( i=1; i&lt;=n; i++) a++;
  print ( a );
  }
  </code></pre>