-- main::(nexting.pl:8)
my $x=1; my $y=2; 
different is on.
-- main::(nexting.pl:9)
$x=$y; $y = 4; $x += $y;
-- main::(nexting.pl:9)
$x=$y; $y = 4; $x += $y;
-- main::(nexting.pl:10)
$x=6; $y = p(); my $z = p(); 
-- main::(nexting.pl:13)
$x = 8;
-- main::(nexting.pl:15)
$x += $z;