Hello,

I have yet another question:
what idea stays belong the fact that code works (OCaml 4.04)

module M = struct
let f v = v+1
module MM = struct
let ff (module R: I) v = R.f v
end
let t v = MM.ff (module M: I) 0
end;;

and that code does not compile

module T = struct
let f ff = ff (module T: I) 0
end;;

?

I understand why second script is wrong but why the first script works?

WBR, ssp