$a=1;$b=2;$c=3;$d=4;$f=5;$g=6;$h=7;
$foo = $a? $b? $c : $d? $e : $f : $g : $h;
print $foo;
__END__
syntax error at C:\temp\ternary.pl line 2, near "$g :"
Execution of C:\temp\ternary.pl aborted due to compilation errors.

##</code><code>##

$foo = $a ? $b ? $c : $d ? $e : $f : $g;

##</code><code>##

$foo = !$a ? $g : $b ? $c : $d ? $e : $f;

##</code><code>##

$foo = !$a ? $g
           : $b ? $c
                : $d ? $e
                     : $f;

##</code><code>##

$foo = $a ? ($b ? $c 
                : ($d ? $e 
                      : $f)) 
          : $g;