[exo13-OCC_cestpluscestmoins.md](https://github.com/user-attachments/files/22254128/exo13-OCC_cestpluscestmoins.md) [exo13-OCC_cestpluscestmoins.py](https://github.com/user-attachments/files/22254243/exo13-OCC_cestpluscestmoins.py) [exo14-OCC_PFC.md](https://github.com/user-attachments/files/22254852/exo14-OCC_PFC.md) [exo14-OCC_PFC.py](https://github.com/user-attachments/files/22254853/exo14-OCC_PFC.py)
