Issue when opening a module

Thank you @jhaberku for your detailled answer! The doc is huge and it is not easy to find the info we need :slight_smile:

About ;;, isn’t it mandatory for multiple lines declarations? Like in:

 let rec getVars (formula : tformula) : VarsSet.t =
    match formula with
    | Value _ -> VarsSet.empty
    | Var var ->  VarsSet.singleton var
    | Not f -> getVars f
    | And (f1, f2) -> VarsSet.union (getVars f1) (getVars f2)
    | Or (f1, f2) -> VarsSet.union (getVars f1) (getVars f2)
    | Implies (f1, f2) -> VarsSet.union (getVars f1) (getVars f2)
    | Equivalent (f1, f2) -> VarsSet.union (getVars f1) (getVars f2);;

? Without ;; the compiler complains on the next line.