src/HOL/BNF/Tools/bnf_fp_util.ML

   val mk_ctor_setN: int -> string
   val mk_dtor_setN: int -> string
   val mk_dtor_set_inductN: int -> string
   val mk_set_inductN: int -> string
 
-  val datatype_word: fp_kind -> string
+  val co_prefix: fp_kind -> string
 
   val base_name_of_typ: typ -> string
   val mk_common_name: string list -> string
 
   val variant_types: string list -> sort list -> Proof.context ->

 val rel_inductN = relN ^ "_" ^ inductN
 val selN = "sel"
 val sel_unfoldN = selN ^ "_" ^ unfoldN
 val sel_corecN = selN ^ "_" ^ corecN
 
-fun datatype_word fp = (if fp = Greatest_FP then "co" else "") ^ "datatype";
+fun co_prefix fp = (if fp = Greatest_FP then "co" else "");
 
 fun add_components_of_typ (Type (s, Ts)) =
     fold add_components_of_typ Ts #> cons (Long_Name.base_name s)
   | add_components_of_typ _ = I;