Update documentation of the Why3 API
I use the Why3 directly in OCaml. In particular I use the
Ptree module. Unfortunately the documentation is very succinct.
For example, I cannot understand what the
Eoptexn constructor does. Is it the declaration of a local exception? Is this local exception caught at the end of the block?
It would be a great improvement if all constructors have their own documentation and it would significantly help the Why3 users.