val is_null : 'a Com.opaque -> bool
val start : int Stdlib.ref
val supply : unit -> string
val named_op : ( 'a -> 'b ) -> string option
val named_op_2 : ( 'a -> 'b -> 'c ) -> string option
val named_op_3 : ( 'a -> 'b -> 'c -> 'd ) -> string option
val named_op_4 : ( 'a -> 'b -> 'c -> 'd -> 'e ) -> string option