val type_info : r -> Ty.t
val str_cmp : r -> r -> int
val hash_cmp : r -> r -> int
val equal : r -> r -> bool
val subst : r -> r -> r -> r
val solve : r -> r -> (r * r) list
val is_a_leaf : r -> bool
val print : Stdlib.Format.formatter -> r -> unit
val abstract_selectors : r -> (r * r) list -> r * (r * r) list
val assign_value : r -> r list -> (Expr.t * r) list -> (Expr.t * bool) option