Add some lemmas about equality of precategories

It's really slow...
After    | File Name                             | Before
-----------------------------------------------------------
1m45.65s | PreCategory/Equality                  |   N/A
0m14.71s | Functor/Equality                      | 0m10.80s
0m06.92s | NaturalTransformation/Equality        | 0m04.18s
0m02.29s | Functor/CompositionLaws               | 0m02.22s
0m02.26s | NaturalTransformation/Composition     | 0m02.15s
0m01.96s | SumPreCategory                        | 0m01.90s
0m01.81s | ProductPreCategory                    | 0m02.22s
0m01.45s | NaturalTransformation/CompositionLaws | 0m01.42s
0m00.29s | NaturalTransformation/Identity        | 0m00.26s
0m00.25s | Common                                | 0m00.20s
0m00.24s | Functor/Composition                   | 0m00.25s
0m00.18s | PreCategory/Core                      |   N/A
0m00.13s | Functor/Core                          | 0m00.12s
0m00.12s | NaturalTransformation/Core            | 0m00.12s
0m00.10s | NaturalTransformation                 | 0m00.07s
0m00.08s | Functor/Identity                      | 0m00.10s
0m00.08s | Utf8                                  | 0m00.09s
0m00.08s | Functor                               | 0m00.08s
0m00.06s | PreCategory                           | 0m00.15s
0m00.05s | NotationsUtf8                         | 0m00.04s
0m00.04s | Notations                             | 0m00.06s
-----------------------------------------------------------
2m18.74s | Total                                 | 0m26.42s