Please list your *top 5* preferred projects for the compiler extension lab. We suggest a number of projects (http://lara.epfl.ch/~gschmid/clp20/extensions.pdf), but feel free to propose your own project ideas. If a custom project idea is unclear from your description below, Georg will contact you via email. If you choose one of our suggested projects, please mention both the identifier and the name (e.g., "4.1 Polymorphic types").