Solution
= Solution
The <full siblings> $E,F$ have parents $G,D$. Since $G$ is noninbred, $\phi_{GG}=1/2$, whereas $\phi_{DD}=5/8$ and $\phi_{GD}=1/8$. Applying the parental <kinship coefficient> recursion to both siblings gives
$$
\boxed{\phi_{EF}=\frac{\phi_{GG}+2\phi_{GD}+\phi_{DD}}4=\frac{1/2+2(1/8)+5/8}{4}=\frac{11}{32}.}
$$
The familiar outbred-sibling value $1/4$ does not apply to this inbred <pedigree>.