$foo = 'This is a CAPITAL test, man';
$bar = 'IS A cap';
if ((lc $foo) =~ (lc $bar)) {
print lc $foo;
print "\n";
print lc $bar;
print "\n";
print 'YES';
}
else {
print lc $foo;
print "\n";
print lc $bar;
print "\n";
print 'NO';
}

##</code><code>##

if (lc $foo =~ lc $bar)