diff -ru dypgen-orig/demos/demo/demo.ml dypgen/demos/demo/demo.ml
--- demos/demo/demo.ml	2026-05-29 06:21:51
+++ demos/demo/demo.ml	2026-05-29 06:21:51
@@ -12,7 +12,7 @@
   exit 0)
 
 let input_file = !string_ref
-let lexbuf = Dyp.from_channel (Parser.pp ()) (Pervasives.open_in input_file)
+let lexbuf = Dyp.from_channel (Parser.pp ()) (Stdlib.open_in input_file)
 let prog = fst (List.hd (Parser.main lexbuf))
 
 let s = str_expr prog
diff -ru dypgen-orig/demos/demo_ocamllex/demo.ml dypgen/demos/demo_ocamllex/demo.ml
--- demos/demo_ocamllex/demo.ml	2026-05-29 06:21:51
+++ demos/demo_ocamllex/demo.ml	2026-05-29 06:21:51
@@ -12,7 +12,7 @@
   exit 0)
 
 let input_file = !string_ref
-let lexbuf = Lexing.from_channel (Pervasives.open_in input_file)
+let lexbuf = Lexing.from_channel (Stdlib.open_in input_file)
 let prog = fst (List.hd (Parser.main Lexer.token lexbuf))
 
 let s = str_expr prog
diff -ru dypgen-orig/demos/demo_ocamllex/parse_tree.ml dypgen/demos/demo_ocamllex/parse_tree.ml
--- demos/demo_ocamllex/parse_tree.ml	2026-05-29 06:21:51
+++ demos/demo_ocamllex/parse_tree.ml	2026-05-29 06:21:51
@@ -22,7 +22,7 @@
 module Ordered_string =
 struct
   type t = string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module String_map = Map.Make(Ordered_string)
diff -ru dypgen-orig/demos/position/position.ml dypgen/demos/position/position.ml
--- demos/position/position.ml	2026-05-29 06:21:51
+++ demos/position/position.ml	2026-05-29 06:21:51
@@ -4,7 +4,7 @@
 let input_file = "input"
 
 let lexbuf = Dyp.from_channel
-  (Position_parser.pp ()) (Pervasives.open_in input_file)
+  (Position_parser.pp ()) (Stdlib.open_in input_file)
 
 let std_lb = Dyp.std_lexbuf lexbuf
 let _ = std_lb.lex_curr_p <-
diff -ru dypgen-orig/demos/position_ocamllex/position.ml dypgen/demos/position_ocamllex/position.ml
--- demos/position_ocamllex/position.ml	2026-05-29 06:21:51
+++ demos/position_ocamllex/position.ml	2026-05-29 06:21:51
@@ -5,7 +5,7 @@
 
 let input_file = "input"
 
-let lexbuf = Lexing.from_channel (Pervasives.open_in input_file)
+let lexbuf = Lexing.from_channel (Stdlib.open_in input_file)
 let _ = lexbuf.lex_curr_p <- { lexbuf.lex_curr_p with pos_fname = input_file }
 let pf = Position_parser.main Position_lexer.token lexbuf
 
diff -ru dypgen-orig/demos/position_token_list/position.ml dypgen/demos/position_token_list/position.ml
--- demos/position_token_list/position.ml	2026-05-29 06:21:51
+++ demos/position_token_list/position.ml	2026-05-29 06:21:51
@@ -5,7 +5,7 @@
 
 let input_file = "input"
 
-let lexbuf = Lexing.from_channel (Pervasives.open_in input_file)
+let lexbuf = Lexing.from_channel (Stdlib.open_in input_file)
 let _ = lexbuf.lex_curr_p <- { lexbuf.lex_curr_p with pos_fname = input_file }
 let lexfun = Position_lexer.token
 
diff -ru dypgen-orig/demos/tinyML/parse_tree.ml dypgen/demos/tinyML/parse_tree.ml
--- demos/tinyML/parse_tree.ml	2026-05-29 06:21:51
+++ demos/tinyML/parse_tree.ml	2026-05-29 06:21:51
@@ -61,7 +61,7 @@
 module Ordered_string =
 struct
   type t = string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module String_map = Map.Make(Ordered_string)
@@ -113,7 +113,7 @@
 module Ordered_op =
 struct
   type t = string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module Op_map = Map.Make(Ordered_op)
diff -ru dypgen-orig/demos/tinyML/tinyML.ml dypgen/demos/tinyML/tinyML.ml
--- demos/tinyML/tinyML.ml	2026-05-29 06:21:51
+++ demos/tinyML/tinyML.ml	2026-05-29 06:21:51
@@ -3,7 +3,7 @@
 open Dyp
 
 let input_file_name = !(Argument.string_ref)
-let input_file = Pervasives.open_in input_file_name
+let input_file = Stdlib.open_in input_file_name
 
 let pp, se_code =
   let (pp:(unit,
diff -ru dypgen-orig/demos/tinyML_ulex/parse_tree.ml dypgen/demos/tinyML_ulex/parse_tree.ml
--- demos/tinyML_ulex/parse_tree.ml	2026-05-29 06:21:51
+++ demos/tinyML_ulex/parse_tree.ml	2026-05-29 06:21:51
@@ -42,7 +42,7 @@
 module Ordered_string =
 struct
   type t = string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module String_map = Map.Make(Ordered_string)
diff -ru dypgen-orig/demos/tinyML_ulex/tinyML.ml dypgen/demos/tinyML_ulex/tinyML.ml
--- demos/tinyML_ulex/tinyML.ml	2026-05-29 06:21:51
+++ demos/tinyML_ulex/tinyML.ml	2026-05-29 06:21:51
@@ -4,7 +4,7 @@
 
 let input_file = !(Argument.string_ref)
 
-let lexbuf = Ulexing.from_utf8_channel (Pervasives.open_in input_file)
+let lexbuf = Ulexing.from_utf8_channel (Stdlib.open_in input_file)
 
 let pf = TinyML_parser.main TinyML_lexer.token lexbuf
 let prog = fst (List.hd pf)
diff -ru dypgen-orig/dypgen/dypgen.ml dypgen/dypgen/dypgen.ml
--- dypgen/dypgen.ml	2026-05-29 06:21:51
+++ dypgen/dypgen.ml	2026-05-29 06:21:51
@@ -26,7 +26,7 @@
 let output_file_mli = input_file_short^".mli"
 
 
-let lexbuf = Lexing.from_channel (Pervasives.open_in input_file)
+let lexbuf = Lexing.from_channel (Stdlib.open_in input_file)
 let () =
   lexbuf.lex_curr_p <- { lexbuf.lex_curr_p with pos_fname = input_file };
   lexbuf.lex_start_p <- { lexbuf.lex_start_p with pos_fname = input_file }
@@ -651,7 +651,7 @@
 module Ordered_str2 =
 struct
   type t = string * string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Str2_map = Map.Make(Ordered_str2)
 
diff -ru dypgen-orig/dypgen/dypgen_parser.ml dypgen/dypgen/dypgen_parser.ml
--- dypgen/dypgen_parser.ml	2026-05-29 06:21:51
+++ dypgen/dypgen_parser.ml	2026-05-29 06:21:51
@@ -784,7 +784,7 @@
 module Ordered_string =
 struct
   type t = string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module String_set = Set.Make(Ordered_string)
diff -ru dypgen-orig/dyplib/automaton.ml dypgen/dyplib/automaton.ml
--- dyplib/automaton.ml	2026-05-29 06:21:51
+++ dyplib/automaton.ml	2026-05-29 06:21:51
@@ -55,7 +55,7 @@
 module Ordered_non_ter =
 struct
   type t = non_ter
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Nt_map = Map.Make(Ordered_non_ter)
 
@@ -75,7 +75,7 @@
 module Ordered_int =
 struct
   type t = int
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Int_set = Set.Make(Ordered_int)
 module Int_map = Map.Make(Ordered_int)
@@ -97,7 +97,7 @@
    (* the int tells whether the rule allows layout characters
     inside or afterwards (see rule options) *)
   let compare l1 l2 =
-    Pervasives.compare l1 l2
+    Stdlib.compare l1 l2
 end
 module Map_rhs = Map.Make (Ordered_rhs)
 
@@ -108,21 +108,21 @@
 module Ordered_items =
 struct
   type t = item
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Item_map = Map.Make(Ordered_items)
 
 module Ordered_token_name =
 struct
   type t = token_name
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module TNS = Set.Make (Ordered_token_name)
 
 module Ordered_intc =
 struct
   type t = int * int
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Intc_map = Map.Make(Ordered_intc)
 module Intc_set = Set.Make(Ordered_intc)
@@ -130,7 +130,7 @@
 module Ordered_predict =
 struct
   type t = (non_ter * (priority nt_prio))
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Predict = Set.Make(Ordered_predict)
 
@@ -196,7 +196,7 @@
     if c<>0 then c else
     let c = Intc_set.compare is1.kernel_nt is2.kernel_nt in
     if c<>0 then c else
-    let c = Pervasives.compare is1.non_kernel is2.non_kernel in
+    let c = Stdlib.compare is1.non_kernel is2.non_kernel in
     if c<>0 then c else Predict.compare is1.predict is2.predict
 
 let soc c = Char.escaped c
@@ -300,7 +300,7 @@
 module Ordered_ntp =
 struct
   type t = priority nt_prio
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Ntp_map = Map.Make(Ordered_ntp)
 
@@ -322,7 +322,7 @@
 module Ordered_lit_trans=
 struct
   type t = lit_trans
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module Map_lit_trans = Map.Make(Ordered_lit_trans)
@@ -338,7 +338,7 @@
     let c = Intc_set.compare is1.kernel_nt is2.kernel_nt in
     if c<>0 then c else
     Intc_set.compare is1.kernel_t is2.kernel_t
-    (*else Pervasives.compare
+    (*else Stdlib.compare
       (is1.reducible,is1.kernel_nt,is1.kernel_t)
       (is2.reducible,is2.kernel_nt,is2.kernel_t)*)
 end
@@ -359,7 +359,7 @@
   module Ordered_States =
   struct
     type t = state
-    let compare s1 s2 = Pervasives.compare s1.number s2.number
+    let compare s1 s2 = Stdlib.compare s1.number s2.number
       (*compare_is s1.items s2.items*)
   end
   module State_set = Set.Make(Ordered_States)
diff -ru dypgen-orig/dyplib/dyp.ml dypgen/dyplib/dyp.ml
--- dyplib/dyp.ml	2026-05-29 06:21:51
+++ dyplib/dyp.ml	2026-05-29 06:21:51
@@ -91,7 +91,7 @@
 module Ordered_urule =
 struct
   type t = nrule
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module Urule_map = Map.Make(Ordered_urule)
@@ -355,7 +355,7 @@
 module Ordered_nrule =
 struct
   type t = nrule
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module RS = Set.Make (Ordered_nrule)
@@ -933,7 +933,7 @@
   type t = (non_ter * priority) * rhs * int
    (* the int tells whether the rule allows layout characters
     inside or afterwards *)
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Rule_map = Map.Make(Ordered_rule)
 
@@ -2012,7 +2012,7 @@
 module Ordered_edge =
 struct
   type t = lit_trans * priority
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Edge_map = Map.Make(Ordered_edge)
 
@@ -2391,7 +2391,7 @@
   with Not_found ->
     let new_lhslist =
       comp_lhslist (nt,ntp) lhslists priodata array_nt_prio in
-    let new_lhslist = List.sort Pervasives.compare new_lhslist in
+    let new_lhslist = List.sort Stdlib.compare new_lhslist in
     try
     let old_nt = make_old_nt nt ntp pdev priodata str_non_ter in
     let old_lhslist =
@@ -2402,7 +2402,7 @@
         nt_of_ind.(i),prio_of_ind.(i),i)
       old_lhslist
     in
-    let old_lhslist = List.sort Pervasives.compare old_lhslist in
+    let old_lhslist = List.sort Stdlib.compare old_lhslist in
     let l = diff_list new_lhslist old_lhslist [] in
     let prio_l = List.map (fun (_,p,_) -> p) l in
     (*Printf.fprintf !log_channel "diff_lhslist res = ";
@@ -3295,9 +3295,9 @@
     | None -> assert false
   in
   if rel then 1 else
-  let c = Pervasives.compare (ind,rhs) (ind1,rhs1) in
+  let c = Stdlib.compare (ind,rhs) (ind1,rhs1) in
   if c<>0 then c else
-  let c = Pervasives.compare start_node.sn_nb
+  let c = Stdlib.compare start_node.sn_nb
     start1.sn_nb in
   if c<>0 then c else
   let rec aux l1 l2 = match l1,l2 with
@@ -3305,7 +3305,7 @@
     | _,[] -> 1
     | [],_ -> -1
     | (e1::t1),(e2::t2) ->
-        let c = Pervasives.compare (snd e1.edge_label)
+        let c = Stdlib.compare (snd e1.edge_label)
           (snd e2.edge_label) in
         if c<>0 then c else aux t1 t2
   in aux p p1
@@ -4825,11 +4825,11 @@
     output_string !log_channel "select_token called\n";
   
   let topmost = List.sort (fun v1 v2 ->
-    Pervasives.compare v1.pdev.lex_nb v2.pdev.lex_nb) topmost in
+    Stdlib.compare v1.pdev.lex_nb v2.pdev.lex_nb) topmost in
   (*let topmost = match topmost with
     | [_] -> topmost
     | _ -> List.sort (fun v1 v2 ->
-        Pervasives.compare v1.pdev.lex_nb v2.pdev.lex_nb)
+        Stdlib.compare v1.pdev.lex_nb v2.pdev.lex_nb)
         topmost
   in*)
   let tbl_l, pdev_l, snll, snl, _ = List.fold_left
@@ -4926,7 +4926,7 @@
     in
     match act_id_l with [] -> None
     | x ->
-    let x = no_double (List.sort Pervasives.compare x) in
+    let x = no_double (List.sort Stdlib.compare x) in
         (*Printf.printf "list x = %s\n"
         (String.concat " " (List.map (fun i -> string_of_int i) x));*)
         Some ((if all_token then x else [select_act_id x]), pdev)
diff -ru dypgen-orig/dyplib/dyplex.ml dypgen/dyplib/dyplex.ml
--- dyplib/dyplex.ml	2026-05-29 06:21:51
+++ dyplib/dyplex.ml	2026-05-29 06:21:51
@@ -214,7 +214,7 @@
 module Ordered_node =
 struct
   type t = node
-  let compare n1 n2 = Pervasives.compare n1.id n2.id
+  let compare n1 n2 = Stdlib.compare n1.id n2.id
 end
 module Node_set = Set.Make(Ordered_node)
 
@@ -436,7 +436,7 @@
         (function ([ci],n1) -> write_interval ci n.id dec_table n1.id
           | _ -> assert false)
         trans_l);
-      final.(n.id) <- List.sort Pervasives.compare (list_of_set n.matched)
+      final.(n.id) <- List.sort Stdlib.compare (list_of_set n.matched)
       (* Is it necessary to sort the list or doesn't
        list_of_set already do it? *))
     sl in
@@ -491,7 +491,7 @@
         (function ([ci],n1) -> write_interval ci n.id dec_table n1.id
           | _ -> assert false)
         trans_l);
-      final.(n.id) <- List.sort Pervasives.compare (list_of_set n.matched)
+      final.(n.id) <- List.sort Stdlib.compare (list_of_set n.matched)
       (* Is it necessary to sort the list or doesn't
        list_of_set already do it? *))
     sl in
diff -ru dypgen-orig/dyplib/priority_by_relation.ml dypgen/dyplib/priority_by_relation.ml
--- dyplib/priority_by_relation.ml	2026-05-29 06:21:51
+++ dyplib/priority_by_relation.ml	2026-05-29 06:21:51
@@ -32,12 +32,12 @@
 module OrdPrio =
 struct
   type t = priority
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 module Ordered_string =
 struct
   type t = string
-  let compare = Pervasives.compare
+  let compare = Stdlib.compare
 end
 
 module Prio_set = Set.Make(OrdPrio)