sub x{ @_[3,4,5,6,8]=(3,4,5,6,939);show(@_)}

##</code><code>##

my @y;$y[3]=undef;

##</code><code>##

x(@y);

##</code><code>##

x($y[0],$y[1],$y[2],$y[3]);

##</code><code>##

@_[3,4,5,6,8]=(3,4,5,6,939);