[mathisgd]

correlated ideas, that I thought were worth sharing:

- formal properties help one understand their own code better. This holds even more true when the properties are high level.

- they are useful to make sure the code behaves as expected, but not only. During the development, it notably helps finding better implementations and reviewing incremental changes.

- the process of outlining properties and drafting their proofs is already valuable, even without formally doing the proofs. It often prompts ideas about more properties and potential bugs.

- a great code is one that makes its rules and invariants obvious. This usually correlates well with general readability.