1#!/usr/bin/perl
2
3# Copyright 2004-2019, Paul Johnson (paul@pjcj.net)
4
5# This software is free.  It is licensed under the same terms as Perl itself.
6
7# The latest version of this software should be available from my homepage:
8# http://www.pjcj.net
9
10use strict;
11use warnings;
12
13my ($x, $p, $q, $r, $s);
14
15$x = 0;
16
17if ($x) {
18    $p++
19}
20
21unless ($x) {
22    $q++
23}
24
25$x = 1;
26
27if ($x) {
28    $r++
29}
30
31if ($x) {
32    $r++
33} else {
34    $s++
35}
36
37unless ($x) {
38    $s++
39}
40