#EXAMPLE 1

OUTER:
  {
  for (@indices)
    {
    $smrow = $sm_rows[$_]; #sm_rows is an array of arrays  #LINE 1
    $omrow = $sm_rows[$mapping[$_]]; #mapping is a 1D vector of integers #LINE 2
    for (@reverse)
      {
      if ( $$smrow[$_] != $$omrow[$mapping[$_] ) #LINE 3
        {
        last OUTER;
        }
      }
    }
  }

#EXAMPLE 2

OUTER:
  {
  for (@indices)
    {
    @smrow = @{$sm_rows[$_]}; #sm_rows is an array of arrays  #LINE 1
    @omrow = @{$sm_rows[$mapping[$_]]}; #mapping is a 1D vector of integers #LINE 2
    for (@reverse)
      {
      if ( $smrow[$_] != $omrow[$mapping[$_] ) #LINE 3
        {
        last OUTER;
        }
      }
    }
  }