So what we want to basically show in this lecture is that whatever the disease is that is described by this pedigree, it cannot be sex linked dominant and it cannot be sex link recessive. And we want to show that this could be autosomal dominant. So show that a disease described by the following pedigree cannot be sex link recessive and sex linked dominant. So as always, to show that it's not something, we have to begin by assuming that it is that. So let's begin by assuming that it is sex length. Let's say recessive.