What is the distribution if an heir acknowledges two uterine (maternal) brothers of the deceased?

Primary text

If an heir acknowledges two uterine brothers of the deceased, one-third of the inheritance in his possession must be given to them. This is because he acknowledges that they are partners in the one-third share belonging to uterine siblings, meaning each is entitled to one-ninth of the total estate. The acknowledging heir possesses one-sixth (which is equivalent to one-ninth plus half of one-ninth), leaving a surplus of half of one-ninth in his possession, which equals one-third of what he holds.