Decode Couples and Lineage from Right to Left

• $S \times T \implies S$ is the wife of $T$ (and $T$ is the husband). • $P \div S \implies P$ is the father of $S$ ($P$ is Wife's father). • $N + P \implies N$ is the mother of $P$ ($N$ is Wife's father's mother). • $M - N \implies M$ is the brother of $N$ ($M$ is Wife's father's mother's brother).

M is Wife's father's mother's brother