let pretty fmt m =
match m with
| Top (t, a) ->
Format.fprintf fmt "{{ mix of %a. Origin: %a}}"
Top_Param.pretty t
Origin.pretty a
| Map m ->
let print_binding k v =
Format.fprintf fmt "@ %a -> %a ;" K.pretty k V.pretty v
in
Format.fprintf fmt "{{" ;
(M.iter print_binding) m;
Format.fprintf fmt "}}"