Conversion.To_Arity
type !'r0 ar0 = D.Context.t -> 'r * D.Context.t
type (!'a0, !'r0) ar1 = 'a -> D.Context.t -> 'r * D.Context.t
type (!'a0, !'b0, !'r0) ar2 = 'a -> 'b -> D.Context.t -> 'r * D.Context.t
type (!'a0, !'b0, !'c0, !'r0) ar3 =
'a ->
'b ->
'c ->
D.Context.t ->
'r * D.Context.t
type (!'a0, !'r0) variadic = 'a list -> D.Context.t -> 'r * D.Context.t