The joint finder

A dictionary holds seven joints. For each one it gives the kind of joint and how much movement it allows. You will look the joints up and sort them.

The idea. A joint is fibrous, cartilaginous or synovial. A synovial joint is written as "synovial, hinge", with its type after the comma.

Your tasks.

1. Finish movement_of. It gives the movement that a joint allows.
2. Finish synovial_joints. It gives the list of the joints whose kind starts with "synovial", in the order of the dictionary.
3. Finish type_of. For a synovial joint it gives the type after the comma, such as "hinge". For another joint it gives the kind itself, such as "fibrous".