Add a get_vars function for mini_calc.
Documentation fix for mini_calc.
Add the mem function in Env's interface for mini_calc.
Merlinization !
Misc modification in lilis engine for better typing and clarity.
Add the new ls_utils module with two verification functions for lsystems.
Remove record in errors, ocaml doesn't handle mutiple record with the same fields very well.
Add error messages in glilis for arity and variable definitions.