$x || $y || $z || 1;

##</code><code>##

[ ~/tmp ] $ perl -we 'use strict; my $x'
[ ~/tmp ] $ perl -we 'my $x'
[ ~/tmp ] $ perl -we '$x'
Useless use of a variable in void context at -e line 1.
Name "main::x" used only once: possible typo at -e line 1.
[ ~/tmp ] $ perl -we 'no warnings qw(once); $x'
[ ~/tmp ] $