--- src/numeric_plugins/mlgmp_plugin.ml.orig	2013-02-14 04:08:25.000000000 -0700
+++ src/numeric_plugins/mlgmp_plugin.ml	2017-12-03 14:00:36.471566987 -0700
@@ -19,48 +19,69 @@
 
 *)
 
-open Gmp
-
-let bits_of_string s =
-  let s' = String.sub s 2 ((String.length s)-2) in (* remove prefix "0b" *)
-  Z.from_string_base ~base:2 s'
+let randobj = Gmp_random.init_default ();
 
 module Mlgmp_int =
 struct
-  type t = Z.t
+  type t = Mpz.t
 
-  let zero = Z.of_int 0
-  let max x y = if Z.cmp x y >= 0 then x else y
-  let min x y = if Z.cmp x y >= 0 then y else x
-  let add = Z.add
-  let neg = Z.neg
-  let mul = Z.mul
-  let div = Z.cdiv_q
-  let pow = Z.pow_ui
-  let compare = Z.cmp
+  let zero = Mpz.of_int 0
+  let max x y = if Mpz.cmp x y >= 0 then x else y
+  let min x y = if Mpz.cmp x y >= 0 then y else x
+  let add x y =
+    let res = Mpz.init () in
+    Mpz.add res x y;
+    res
+  let neg x =
+    let res = Mpz.init () in
+    Mpz.neg res x;
+    res
+  let mul x y =
+    let res = Mpz.init () in
+    Mpz.mul res x y;
+    res
+  let div x y =
+    let res = Mpz.init () in
+    Mpz.cdiv_q res x y;
+    res
+  let pow x y =
+    let res = Mpz.init () in
+    Mpz.pow_ui res x y;
+    res
+  let compare = Mpz.cmp
   let random n =
-    bits_of_string (Random_generator.to_string n)
-  let of_int = Z.from_int
-  let of_string x =
-    try
-      Z.from_string_base ~base:10 x
-    with Invalid_argument _ ->
-      raise (Failure ("Mpzf.of_string: "^x^" is not well-formatted"))
-  let to_string = Z.to_string_base ~base:10
+    let res = Mpz.init () in
+    Gmp_random.Mpz.urandomb res randobj n;
+    res
+  let of_int = Mpz.of_int
+  let of_string = Mpz.of_string
+  let to_string = Mpz.get_str ~base:10
 end
 
 module Mlgmp_rat =
 struct
-  type t = Q.t
+  type t = Mpq.t
 
-  let zero = Q.from_int 0
-  let one = Q.from_int 1
-  let max x y = if Q.cmp x y >= 0 then x else y
-  let min x y = if Q.cmp x y >= 0 then y else x
-  let add = Q.add
-  let neg = Q.neg
-  let mul = Q.mul
-  let div = Q.div
+  let zero = Mpq.of_int 0
+  let one = Mpq.of_int 1
+  let max x y = if Mpq.cmp x y >= 0 then x else y
+  let min x y = if Mpq.cmp x y >= 0 then y else x
+  let add x y =
+    let res = Mpq.init () in
+    Mpq.add res x y;
+    res
+  let neg x =
+    let res = Mpq.init () in
+    Mpq.neg res x;
+    res
+  let mul x y =
+    let res = Mpq.init () in
+    Mpq.mul res x y;
+    res
+  let div x y =
+    let res = Mpq.init () in
+    Mpq.div res x y;
+    res
 
   let pow x n =
     let rec pow_aux x n =
@@ -68,31 +89,29 @@ struct
       if n = 0 then one
       else
         let y = pow_aux x (n/2) in
-        let z = mul y y in
-        if n mod 2 = 0 then
-          z
-        else
-          mul x z
+        let z = Mpq.init () in
+        Mpq.mul z y y;
+        if n mod 2 != 0 then
+          Mpq.mul z x z;
+        z
     in
     if n >= 0 then
       pow_aux x n
     else
-      pow_aux (Q.inv x) (-n)
+      pow_aux (Mpq.inv x x; x) (-n)
 
-  let compare = Q.cmp
+  let compare = Mpq.cmp
   let random n =
-    let num = bits_of_string (Random_generator.to_string n) in
-    let den = bits_of_string (Random_generator.to_string n) in
-    Q.div (Q.from_z num) (Q.add Q.one (Q.from_z den))
-  let of_int = Q.from_int
-  let of_string x =
-    try
-      let i = String.index x '/' in
-      let num = Z.from_string_base ~base:10 (String.sub x 0 i) in
-      let den = Z.from_string_base ~base:10 (String.sub x (i+1) ((String.length x)-(i+1))) in
-      Q.div (Q.from_z num) (Q.from_z den)
-    with Not_found -> Q.from_z (Z.from_string_base ~base:10 x)
-  let to_string = Q.to_string
+    let num = Mpz.init () in
+    let den = Mpz.init () in
+    Gmp_random.Mpz.urandomb num randobj n;
+    Gmp_random.Mpz.urandomb den randobj n;
+    let res = Mpq.init () in
+    Mpq.div res (Mpq.init_set_z num) (Mpq.add res one (Mpq.init_set_z den); res);
+    res
+  let of_int = Mpq.of_int
+  let of_string = Mpq.of_string
+  let to_string = Mpq.to_string
 end
 
 let _ =