## The left side is false, so it short circuits 
## and the residual value assigned is 0
my $x = $zero && $two;

## The left side is true, so it checks the right side which is false; 
## so the residual value comes from the right side and is 0
my $y = $three && $zero;

## The left side is true, so it checks the right side which is also true; 
## so the residual value comes from the right side and is 3
my $z = $two && $three;