| C.LetIn (n,s,ty,t) ->
(* only to check if s is well-typed *)
let ty',ugraph1 = type_of_aux ~logger context s ugraph in
+ let _,ugraph1 = type_of_aux ~logger context ty ugraph1 in
let b,ugraph1 =
R.are_convertible ~subst ~metasenv context ty ty' ugraph1
in