print "above\n";
  my $E = binary($k);
  print "below\n";

##</code><code>##

  print "x\n";
  print "y\n";
  print "z\n";

##</code><code>##

# How many steps we want to take
my $steps = 3;

sub recur
{
	my ($x) = @_;

	# Create a number of leading spaces equal to our current $x
	my $ldr = " " x $x;

	# Note that we're starting
	print "${ldr}Start with $x\n";

	# We only go to $steps to make it a smallish example
	if($x >= $steps)
	{
		print "${ldr}At $steps, returning.\n";
		return;
	}

	# Recurse with the next number.  Say we're doing it, do it, say we're
	# done.
	my $y = $x + 1;
	print "${ldr}-> Subcall with $y\n";
	recur($y);
	print "${ldr}<- Back from $y\n";

	# And now we're done with this number, so step back
	print "${ldr}Done with $x\n";
}

# Start off
recur(0);

##</code><code>##

% ./tst.pl 
Start with 0
-> Subcall with 1
 Start with 1
 -> Subcall with 2
  Start with 2
  -> Subcall with 3
   Start with 3
   At 3, returning.
  <- Back from 3
  Done with 2
 <- Back from 2
 Done with 1
<- Back from 1
Done with 0