Question

Suppose that Prolog facts are used to define the predicates mother $\left(M,Y\right)$ and father $\left(F,X\right)$,which represent that Mis the mother of Yand Fis the father of X, respectively. Give a Prolog rule to define the predicate sibling $\mathbf{(}\mathit{X}\mathbf{,}\mathit{Y}\mathbf{)}$, which represents that Xand Yare siblings (that is, have the same mother and the same father).

Short answer

Sibling $(X,Y)$: - mother $\left(M,X\right)$, father $\left(F,X\right)$, mother $\left(M,Y\right)$, father$\left(F,Y\right)$

Step-by-step solution

Given information

Prolog facts are used to define the predicates mother $\left(M,Y\right)$and father $\left(F,X\right)$which represent that M is a mother of Y and F is the father of X respectively.

Prolog rule to define the predicate sibling(X,Y)

Sibling $(X,Y)$: - mother $\left(M,X\right)$, father $\left(F,X\right)$, mother $\left(M,Y\right)$, father$\left(F,Y\right)$

Where, :- means define and , represents a conjunction.