Write axioms describing the predicates
${Grandchild}$, ${Greatgrandparent}$, ${Ancestor}$, ${Brother}$,
${Sister}$, ${Daughter}$, ${Son}$, ${FirstCousin}$,
${BrotherInLaw}$, ${SisterInLaw}$, ${Aunt}$, and ${Uncle}$. Find
out the proper definition of $m$th cousin $n$ times removed, and write
the definition in first-order logic. Now write down the basic facts
depicted in the family tree in Figure family1-figure.
Using a suitable logical reasoning system, it all the sentences you have
written down, and it who are Elizabeth’s grandchildren, Diana’s
brothers-in-law, Zara’s great-grandparents, and Eugenie’s ancestors.
A typical family tree. The symbol $\bowtie$ connects spouses and arrows point to children.
