         .          |
|                 /       |       \                       .           |
|                /        |        \                     .            |
|            F a c t      B      F a c t                .             |
|              /       Evolute       \                 .              |
|             /     Comprehension     \               .               |
|            /      *           *      \             .                |
|           /     *               *     \           .     