Propositiones ad Acuendos Juvenes/Problems/11 - De Duobus Hominibus Singulas Sorores Accipientibus/Variant 2

by : Problem $\text {11 b}$

 * De Patre et Filio et Vidua Eiusque Filia: A father and son and a widow and her daughter


 * If a relict or widow and her daughter take a father and son in marriage,
 * so that the son marries the mother and the father marries the daughter,
 * what is the relationship of their sons?

Solution
Each son is simultaneously the nephew and the uncle of the other.


 * Let son $1$ be the son of Father and Daughter.
 * Let son $2$ be the son of Son and Mother.

Then:


 * $(1): \quad$ Son $1$ and Son are both the sons of Father, which makes son $1$ the uncle of son $2$

and at the same time:
 * $(2): \quad$ Son $2$ and Daughter are both the children of Mother, which makes son $1$ the nephew of son $2$

and vice versa.