answer(index_value, pair(0, red)).
answer(index_value, pair(1, green)).
answer(index_value, pair(2, blue)).
answer(bound_index, green).
answer(set_first, [blue, green]).
answer(set_last, [a, b, z]).
answer(index_too_large_rejected, ok).
answer(set_too_large_rejected, ok).