Is the maternal uncle of the maternal uncle a mahram (a relative one may not marry) for a woman?

Question:
Is my maternal uncle’s maternal uncle considered a mahram (a relative one may not marry) for me?

Answer:
In any case: if he is the brother of your maternal grandmother, then he is your maternal uncle. Your maternal uncle’s maternal uncle becomes the brother of your maternal grandmother, and she is your grandmother; so he is your maternal uncle. This is because a woman’s maternal uncle is the maternal uncle of her children, and her maternal uncle’s brother is the maternal uncle of her children. However, if he is the maternal uncle of your maternal uncle because he is the brother of his mother, and the maternal uncle of the maternal uncle is not the brother of your mother, then he is not your maternal uncle unless he is a maternal uncle to you and a maternal uncle to your mother.
So the point is: if your maternal uncle is the brother of your mother, and his maternal uncle is the brother of the maternal grandmother of all of you, then there is no harm; he is your maternal uncle.