enum Random\IntervalBoundary
{
    
         case  ClosedOpen
     ; //
      A right-open interval.
      The lower boundary is included in the interval,
      the upper boundary is not.
     
    
    
         case  ClosedClosed
     ; //
      A closed interval.
      Both boundary values are included in the interval.
     
    
    
         case  OpenClosed
     ; //
      A left-open interval.
      The upper boundary is included in the interval,
      the lower boundary is not.
     
    
    
         case  OpenOpen
     ; //
      An open interval.
      Neither boundary value is included in the interval.
     
    
   }