Poly: Solved exercises mumble_grumble and baz_num_elts.
Poly: Solved exercise poly_exercises.
Poly: Solved zip_checks and split.
Poly: Solved ohead_poly.
Poly: Solved currying.
Poly: Solved filter_even_gt7.
Poly: Solved partition.
Poly: Solved map_rev.
Poly: Solved flat_map.
Poly: Solved fold_types_different.
Poly: Solved override_example.
Poly: Solved override_neq.
Poly: Solved folding/unfolding.
Poly: Solved fold_size and fold_map.