src/Tools/Code/code_ml.ML

   let
     val thy = ProofContext.theory_of background;
     val tyco = Sign.intern_type thy raw_tyco;
     val constrs = map (Code.check_const thy) raw_constrs;
     val constrs' = (map fst o snd o Code.get_datatype thy) tyco;
-    val _ = if gen_eq_set (op =) (constrs, constrs') then ()
+    val _ = if eq_set (op =) (constrs, constrs') then ()
       else error ("Type " ^ quote tyco ^ ": given constructors diverge from real constructors")
     val is_first = is_first_occ background;
     val background' = register_datatype tyco constrs background;
   in (print_code struct_name is_first (print_datatype tyco constrs), background') end;