- remove useless ra_ prefixes in src/ files

- some tutorial file
- dune support ?


- exploit universe polymorphism (see file rel.v)

- rebase lattice.ops on top of a setoid structure ?

- complete lattice operations / theory ?

- more efficient decision procedure for KAT

- KAPT
- tactics for Kleene algebra with top/converse
- tactics for residuals

- have [ka] work without 0
