extension_example(all_colors_are_atoms, true).
extension_example(successors, [1 - 2, 2 - 3, 3 - 4]).
extension_example(collection_with_tail, [red, green, blue, done]).
extension_example(repeated_variable_variant, true).
extension_example(different_variable_shape, true).
extension_example(color_count, 3).