#!/usr/bin/perl
# Copyright 2004-2017, Paul Johnson (paul@pjcj.net)
# This software is free. It is licensed under the same terms as Perl itself.
# The latest version of this software should be available from my homepage:
# http://www.pjcj.net
use strict;
use warnings;
my ($x, $p, $q, $r, $s);
$x = 0;
if ($x) {
$p++
}
unless ($x) {
$q++
}
$x = 1;
if ($x) {
$r++
}
if ($x) {
$r++
} else {
$s++
}
unless ($x) {
$s++
}