true.

?- has_ancestor(Who1, Who2).
Who1 = edward_duke,
Who2 = amelia ;;
Who1 = victoria,
Who2 = victoria_s_c ;;
Who1 = edward,
Who2 = victoria ;;
Who1 = alice,
Who2 = victoria ;;
Who1 = edward_duke,
Who2 = george_iv ;;
Who1 = victoria,
Who2 = edward_duke ;;
Who1 = edward,
Who2 = albert ;;
Who1 = alice,
Who2 = albert ;;
Who1 = edward,
Who2 = victoria_s_c ;;
Who1 = edward,
Who2 = edward_duke ;;
Who1 = edward,
Who2 = amelia ;;
Who1 = edward,
Who2 = george_iv ;;
Who1 = alice,
Who2 = victoria_s_c ;;
Who1 = alice,
Who2 = edward_duke ;;
Who1 = alice,
Who2 = amelia ;;
Who1 = alice,
Who2 = george_iv ;;
Who1 = victoria,
Who2 = amelia ;;
Who1 = victoria,
Who2 = george_iv ;;
false.

?- halt.