diff --git a/information_theory/channel.v b/information_theory/channel.v
index edbda8c3..30557a04 100644
--- a/information_theory/channel.v
+++ b/information_theory/channel.v
@@ -240,7 +240,7 @@ Lemma Pr_DMC_fst (Q : 'rV_n -> bool) :
 Proof.
 rewrite {1}/Pr big_rV_prod /= -(pair_big_fst _ _ [pred x | Q x]) //=; last first.
   move=> t /=.
-  rewrite SetDef.pred_of_setE /= SetDef.finsetE /= ffunE. (* TODO: clean? *)
+  set X := (X in X _ = _); transitivity (prod_rV t \in X) => //; rewrite inE/=.
   congr (Q _).
   by apply/rowP => a; rewrite !mxE.
 transitivity (\sum_(i | Q i) P `^ n i * (\sum_(y in 'rV[B]_n) W ``(y | i))).
@@ -259,7 +259,7 @@ Lemma Pr_DMC_out m (S : {set 'rV_m}) :
 Proof.
 rewrite {1}/Pr big_rV_prod /= -(pair_big_snd _ _ [pred x | x \notin S]) //=; last first.
   move=> tab /=.
-  rewrite SetDef.pred_of_setE /= SetDef.finsetE /= ffunE. (* TODO: clean *)
+  set X := (X in X _ = _); transitivity (prod_rV tab \in X) => //; rewrite inE/=.
   do 2 f_equal.
   by apply/rowP => a; rewrite !mxE.
 rewrite /= /Pr /= exchange_big /=; apply: eq_big => tb; first by rewrite !inE.
diff --git a/information_theory/entropy.v b/information_theory/entropy.v
index 936e61f8..a99951cb 100644
--- a/information_theory/entropy.v
+++ b/information_theory/entropy.v
@@ -1,8 +1,8 @@
 (* infotheo: information theory and error-correcting codes in Coq             *)
 (* Copyright (C) 2020 infotheo authors, license: LGPL-2.1-or-later            *)
-From mathcomp Require Import all_ssreflect all_algebra fingroup perm matrix.
+From mathcomp Require Import all_ssreflect all_algebra fingroup perm.
 Require Import Reals.
-From mathcomp Require Import Rstruct.
+From mathcomp Require Import Rstruct reals.
 Require Import ssrR Reals_ext realType_ext ssr_ext ssralg_ext bigop_ext.
 Require Import logb ln_facts fdist jfdist_cond proba binary_entropy_function.
 Require Import divergence.
@@ -386,8 +386,8 @@ move=> j; rewrite /put_back /put_front; case: (ifPn (j == i)) => [ji|].
 rewrite neq_ltn => /orP[|] ji.
   rewrite ji ifF; last first.
     apply/negbTE/eqP => /(congr1 val) => /=.
-    by rewrite inordK // ltnS (leq_trans ji) // -ltnS.
-  rewrite inordK; last by rewrite ltnS (leq_trans ji) // -ltnS.
+    by rewrite inordK // ltnS (leq_trans ji) // -ltnS/=.
+  rewrite inordK; last by rewrite ltnS (leq_trans ji) // -ltnS/=.
   by rewrite ji /=; apply val_inj => /=; rewrite inordK.
 rewrite ltnNge (ltnW ji) /= ifF; last first.
   by apply/negbTE; rewrite -lt0n (leq_trans _ ji).
@@ -418,7 +418,7 @@ transitivity (\sum_(x : A) P
     move: ji; rewrite neq_ltn => /orP[|] ji.
       apply val_inj => /=.
       rewrite inordK; last first.
-        by rewrite /unbump (ltnNge i j) (ltnW ji) subn0 (leq_trans ji) // -ltnS.
+        by rewrite /unbump (ltnNge i j) (ltnW ji) subn0 (leq_trans ji) // -ltnS/=.
       by rewrite unbumpK //= inE ltn_eqF.
     apply val_inj => /=.
     rewrite inordK; last first.
@@ -442,12 +442,12 @@ rewrite neq_ltn => /orP[|] ki.
   rewrite (_ : inord _ = rshift 1 (inord k)); last first.
     apply/val_inj => /=.
     rewrite add1n inordK /=.
-      by rewrite inordK // (leq_trans ki) // -ltnS.
-    by rewrite ltnS (leq_trans ki) // -ltnS.
+      by rewrite inordK // (leq_trans ki) // -ltnS/=.
+    by rewrite ltnS (leq_trans ki) // -ltnS/=.
   rewrite (@row_mxEr _ _ 1); congr (v ``_ _).
   apply val_inj => /=.
   rewrite /unbump ltnNge (ltnW ki) subn0 inordK //.
-  by rewrite (leq_trans ki) // -ltnS.
+  by rewrite (leq_trans ki) // -ltnS/=.
 rewrite ltnNge (ltnW ki) /=; move: ki.
 have [/eqP -> //|k0] := boolP (k == ord0).
 rewrite (_ : k = rshift 1 (inord k.-1)); last first.
@@ -691,7 +691,8 @@ Lemma cdiv1_ge0 z : 0 <= cdiv1 z.
 Proof.
 have [z0|z0] := eqVneq (PQR`2 z) 0.
   apply/RleP/sumr_ge0 => -[a b] _; apply/RleP.
-  by rewrite {1}/jcPr setX1 Pr_set1 (dom_by_fdist_snd _ z0) div0R mul0R.
+  rewrite {1}/jcPr setX1 [X in X / _ * _]Pr_set1/= (dom_by_fdist_snd (a, b) z0).
+  by rewrite div0R mul0R.
 have Hc : (fdistX PQR)`1 z != 0 by rewrite fdistX1.
 have Hc1 : (fdistX (fdist_proj13 PQR))`1 z != 0.
   by rewrite fdistX1 fdist_proj13_snd.
@@ -1088,15 +1089,14 @@ have -> : cond_entropy PY = \sum_(j < n.+1)
     rewrite 2!fdist_sndE; congr (_ * _).
       apply eq_bigr => a _.
       rewrite -H2.
-      congr (fdistX _ (a, castmx (_, _) _)).
-      exact: eq_irrelevance.
+      by rewrite (_ : esym H1 = H1).
     rewrite /cond_entropy1; congr (- _).
     apply eq_bigr => a _.
     rewrite /jcPr /Pr !big_setX /= !big_set1.
     rewrite !H2 //=.
     congr (_ / _ * log (_ / _)).
-    + rewrite 2!fdist_sndE; apply eq_bigr => a' _; by rewrite H2.
-    + rewrite 2!fdist_sndE; apply eq_bigr => a' _; by rewrite H2.
+    + by rewrite 2!fdist_sndE; apply eq_bigr => a' _; rewrite H2.
+    + by rewrite 2!fdist_sndE; apply eq_bigr => a' _; rewrite H2.
 rewrite -addR_opp big_morph_oppR -big_split /=; apply eq_bigr => j _ /=.
 case: ifPn => j0.
 - rewrite mutual_infoE addR_opp; congr (`H _ - _).
@@ -1234,7 +1234,7 @@ transitivity (Pr PRQ [set x] / Pr Q [set x.2]).
 transitivity (Pr PQ [set (x.1.1,x.2)] * \Pr_RQ[[set x.1.2]|[set x.2]] / Pr Q [set x.2]).
   congr (_ / _).
   case: x H0 => [[a c] b] H0 /=.
-  rewrite /PRQ Pr_set1 fdistACE /= mc; congr (_ * _).
+  rewrite /PRQ [LHS]Pr_set1 fdistACE /= mc; congr (_ * _).
   rewrite /jcPr {2}/QP fdistX2 -/P Pr_set1 mulRCA mulRV ?mulR1; last first.
     apply dom_by_fdist_fstN with b.
     apply dom_by_fdist_fstN with c.
diff --git a/information_theory/kraft.v b/information_theory/kraft.v
index 9428de7f..c742ef4b 100644
--- a/information_theory/kraft.v
+++ b/information_theory/kraft.v
@@ -139,7 +139,7 @@ Program Definition ary_of_nat'
       else
         rcons (f (n %/ t) _) (inord (n %% t))
   end.
-Next Obligation. exact/ltP/ltn_Pdiv. Qed.
+Next Obligation. by move=> n ? ? <-; apply/ltP/ltn_Pdiv. Qed.
 
 Definition ary_of_nat := Fix Wf_nat.lt_wf (fun _ => seq 'I_t) ary_of_nat'.
 
@@ -493,6 +493,7 @@ End kraft_condition.
 Program Definition prepend (T : finType) (lmax : nat) (c : seq T) (t : (lmax - size c).-tuple T)
   : lmax.-tuple T := @Tuple _ _ (take lmax c ++ t) _.
 Next Obligation.
+move=> T lmax c t.
 rewrite size_cat size_take size_tuple.
 case: ifPn.
   move/ltnW; rewrite -subn_eq0 => /eqP ->; by rewrite addn0.
diff --git a/information_theory/source_code.v b/information_theory/source_code.v
index e167c2b1..bb9146e5 100644
--- a/information_theory/source_code.v
+++ b/information_theory/source_code.v
@@ -1,6 +1,6 @@
 (* infotheo: information theory and error-correcting codes in Coq               *)
 (* Copyright (C) 2020 infotheo authors, license: LGPL-2.1-or-later              *)
-From mathcomp Require Import all_ssreflect ssralg matrix.
+From mathcomp Require Import all_ssreflect ssralg ssrnum matrix.
 Require Import Reals.
 From mathcomp Require Import Rstruct.
 Require Import ssrR Reals_ext logb fdist proba.
@@ -40,7 +40,7 @@ Variables (A : finType) (k n : nat).
 
 Definition scode_vl := scode A (seq bool) k.
 
-Variables (P : {fdist A}) (f : {RV (P `^ n) -> seq bool}).
+Variables (P : R.-fdist A) (f : {RV (P `^ n) -> seq bool}).
 
 Definition E_leng_cw := `E ((INR \o size) `o f).
 
diff --git a/probability/necset.v b/probability/necset.v
index 8a6d5ab9..e799ab3e 100644
--- a/probability/necset.v
+++ b/probability/necset.v
@@ -174,6 +174,9 @@ End neset_lemmas.
 Local Hint Resolve repr_in_neset : core.
 (*Arguments image_neset : simpl never.*)
 
+#[short(type=necset)]
+HB.structure Definition NECSet (A : convType) := {X of @isConvexSet A X & @isNESet A X}.
+
 Section conv_set_def.
 Local Open Scope classical_set_scope.
 Local Open Scope R_scope.
@@ -197,7 +200,6 @@ Lemma conv_pt_setE p x Y : x <| p |>: Y = (fun y => x <| p |> y) @` Y.
 Proof. by rewrite /conv_pt_set; unlock. Qed.
 
 Definition conv_set p (X Y : set L) := \bigcup_(x in X) (x <| p |>: Y).
-Local Notation "X :<| p |>: Y" := (conv_set p X Y).
 End conv_set_def.
 
 Notation "x <| p |>: Y" := (conv_pt_set p x Y) : convex_scope.
@@ -357,7 +359,7 @@ by move/asboolP: (convex_setP Y); apply.
 Qed.
 
 (*Canonical conv_pt_cset*)
-HB.instance Definition _ (p : {prob R}) (x : A) (Y : {convex_set A}) := 
+HB.instance Definition _ (p : {prob R}) (x : A) (Y : {convex_set A}) :=
   isConvexSet.Build _ _ (conv_pt_cset_is_convex p x Y).
 
 Lemma conv_cset_is_convex (p : {prob R}) (X Y : {convex_set A}) :
@@ -868,9 +870,6 @@ HB.instance Definition _ (*biglubDr_semiLattConvType*) := @isSemiLattConv.Build
 
 End semicompsemilattconvtype_lemmas.
 
-#[short(type=necset)]
-HB.structure Definition NECSet (A : convType) := {X of @isConvexSet A X & @isNESet A X}.
-
 Section necset_canonical.
 Variable (A : convType).
 Canonical necset_predType :=
@@ -910,20 +909,14 @@ HB.instance Definition _ {A : convType} p (X Y : necset A) :=
 HB.instance Definition _ {A : convType} p (X Y : necset A) :=
   ConvexSet.on (necset_convType_conv p X Y).*)
 
+HB.instance Definition _ {A : convType} (p : {prob R}) (X Y : necset A) :=
+  isNESet.Build _ _ (conv_set_neq0 p X Y).
+
 Module necset_convType.
 Section def.
 Variable A : convType.
 
-Definition necset_convType_conv p (X Y : necset A) :=
-  X :<|p|>: Y.
-
-HB.instance Definition _ p (X Y : necset A) :=
-  NESet.on (necset_convType_conv p X Y).
-
-HB.instance Definition _ p (X Y : necset A) :=
-  ConvexSet.on (necset_convType_conv p X Y).
-
-Definition conv p (X Y : necset A) : necset A := necset_convType_conv p X Y.
+Definition conv p (X Y : necset A) : necset A := X :<|p|>: Y.
 
 (*locked
   (NECSet.Pack (NECSet.Class (isConvexSet.Build _ _ (conv_cset_is_convex p X Y))
@@ -943,7 +936,7 @@ Proof. by apply necset_ext; rewrite !convE convC_set. Qed.
 
 Lemma convA p q X Y Z :
   conv p X (conv q Y Z) = conv [s_of p, q] (conv [r_of p, q] X Y) Z.
-Proof. by apply necset_ext; rewrite !convE convA_set. Qed.
+Proof. by apply: necset_ext; rewrite 2!convE convA_set. Qed.
 
 End def.
 
@@ -977,22 +970,19 @@ Local Open Scope classical_set_scope.
 Variable (A : convType).
 
 Definition pre_op (X : neset {necset A}) : {convex_set A} :=
-  ConvexSet.Pack (ConvexSet.Class
-    (isConvexSet.Build _ _ (hull_is_convex (\bigcup_(i in X) idfun i)%:ne))).
+  hull (\bigcup_(i in X) idfun i)%:ne.
 
 Lemma pre_op_neq0 X : pre_op X != set0 :> set _.
 Proof. by rewrite hull_eq0 neset_neq0. Qed.
 
 Definition biglub_necset (X : neset (necset A)) : necset A :=
-  NECSet.Pack (NECSet.Class
-    (CSet.Mixin (hull_is_convex (\bigcup_(i in X) idfun i)%:ne))
-    (NESet.Mixin (pre_op_neq0 X))).
+  hull (\bigcup_(i in X) idfun i)%:ne.
 
 Lemma biglub_necset1 x : biglub_necset [set x]%:ne = x.
-Proof. by apply necset_ext => /=; rewrite bigcup_set1 hull_cset. Qed.
+Proof. by apply: necset_ext => /=; rewrite bigcup_set1 hull_cset. Qed.
 
 Lemma biglub_necset_bigsetU (I : Type) (S : neset I) (F : I -> neset (necset A)) :
-  biglub_necset (bignesetU S F) = biglub_necset (biglub_necset @` (F @` S))%:ne.
+  biglub_necset (\bigcup_(i in S) F i) = biglub_necset (biglub_necset @` (F @` S))%:ne.
 Proof.
 apply necset_ext => /=.
 apply: hull_eqEsubset => a.
@@ -1013,7 +1003,7 @@ Qed.
 
 Let lub_ (x y : necset A) : necset A := biglub_necset [set x; y]%:ne.
 
-Let lub_E (x y : necset A) : lub_ x y = neset_hull_necset (x `|` y)%:ne.
+Let lub_E (x y : necset A) : lub_ x y = hull (x `|` y)%:ne.
 Proof. by apply necset_ext; rewrite /= bigcup_setU !bigcup_set1. Qed.
 
 Let lub_C : commutative lub_.
@@ -1032,7 +1022,7 @@ by move=> x; rewrite lub_E; apply necset_ext => /=; rewrite setUid hull_cset.
 Qed.
 
 #[export]
-HB.instance Definition _ := @isSemiLattice.Build (necset A) (Choice.class _)
+HB.instance Definition _ := @isSemiLattice.Build (necset A)
   lub_ lub_C lub_A lub_xx.
 
 Let lub_E' : forall x y, lub_ x y = biglub_necset [set x; y]%:ne.
@@ -1040,7 +1030,7 @@ Proof. by []. Qed.
 
 #[export]
 HB.instance Definition _ (*necset_semiCompSemiLattType*) :=
-  @isSemiCompSemiLatt.Build (necset A) (Choice.class _)
+  @isSemiCompSemiLatt.Build (necset A)
     biglub_necset biglub_necset1 biglub_necset_bigsetU lub_E'.
 
 End def.
@@ -1057,7 +1047,9 @@ Let biglubDr' (p : {prob R}) (X : L) (I : neset L) :
   necset_convType.conv p X (|_| I) = |_| ((necset_convType.conv p X) @` I)%:ne.
 Proof.
 apply necset_ext => /=.
-rewrite -hull_cset necset_convType.conv_conv_set /= hull_conv_set_strr.
+rewrite -[LHS]hull_cset/=.
+rewrite [X in hull X = _]necset_convType.conv_conv_set /=.
+rewrite hull_conv_set_strr.
 congr hull; rewrite eqEsubset; split=> u /=.
 - case=> x Xx [] y []Y IY Yy <-.
   exists (necset_convType.conv p X Y); first by exists Y.
@@ -1094,7 +1086,7 @@ Module necset_join.
 Section def.
 Local Open Scope classical_set_scope.
 Local Open Scope proba_scope.
-Definition F (T : Type) := {necset {dist (choice_of_Type T)}}.
+Definition F (T : Type) := {necset {dist {classic T}}}.
 Variable T : Type.
 
 Definition L := [the convType of F T].
@@ -1120,12 +1112,12 @@ Qed.
 Definition L' := necset L.
 
 Definition F1join0 : FFT -> L' := fun X => NECSet.Pack (NECSet.Class
-  (CSet.Mixin (F1join0'_convex X)) (NESet.Mixin (F1join0'_neq0 X))).
+  (isConvexSet.Build _ _ (F1join0'_convex X)) (isNESet.Build _ _ (F1join0'_neq0 X))).
 
 Definition join1' (X : L')
-    : convex_set [the convType of {dist (choice_of_Type T)}] :=
-  CSet.Pack (CSet.Mixin (hull_is_convex
-    (\bigcup_(i in X) if i \in X then (i : set _) else cset0 _))).
+    : {convex_set [the convType of {dist {classic T}}]} :=
+  ConvexSet.Pack (ConvexSet.Class (isConvexSet.Build _ _ (hull_is_convex
+    (\bigcup_(i in X) if i \in X then (i : set _) else set0)))).
 
 Lemma join1'_neq0 (X : L') : join1' X != set0 :> set _.
 Proof.
@@ -1138,8 +1130,8 @@ by rewrite sy.
 Qed.
 
 Definition join1 : L' -> L := fun X =>
-  NECSet.Pack (NECSet.Class (CSet.Mixin (hull_is_convex _))
-                            (NESet.Mixin (join1'_neq0 X))).
+  NECSet.Pack (NECSet.Class (isConvexSet.Build _ _ (hull_is_convex _))
+                            (isNESet.Build _ _ (join1'_neq0 X))).
 Definition join : FFT -> L := join1 \o F1join0.
 End def.
 Module Exports.
@@ -1156,14 +1148,14 @@ Local Notation M := (necset_join.F).
 
 Section ret.
 Variable a : Type.
-Definition necset_ret (x : a) : M a := necset1 (fsdist1 (x : choice_of_Type a)).
+Definition necset_ret (x : a) : M a := [set (fsdist1 (x : {classic a}))].
 End ret.
 
 Section fmap.
 Variables (a b : Type) (f : a -> b).
 
 Let necset_fmap' (ma : M a) :=
-  (fsdistmap (f : choice_of_Type a -> choice_of_Type b)) @` ma.
+  (fsdistmap (f : {classic_ a} -> {classic b})) @` ma.
 
 Lemma necset_fmap'_convex ma : is_convex_set (necset_fmap' ma).
 Proof.
@@ -1175,12 +1167,12 @@ Qed.
 Lemma necset_fmap'_neq0 ma : (necset_fmap' ma) != set0.
 Proof.
 case/set0P : (neset_neq0 ma) => x max; apply/set0P.
-by exists (fsdistmap (f : choice_of_Type a -> choice_of_Type b) x), x.
+by exists (fsdistmap (f : {classic a} -> {classic b}) x), x.
 Qed.
 
 Definition necset_fmap : M a -> M b := fun ma =>
-  NECSet.Pack (NECSet.Class (CSet.Mixin (necset_fmap'_convex ma))
-                            (NESet.Mixin (necset_fmap'_neq0 ma))).
+  NECSet.Pack (NECSet.Class (isConvexSet.Build _ _ (necset_fmap'_convex ma))
+                            (isNESet.Build _ _ (necset_fmap'_neq0 ma))).
 End fmap.
 
 Section bind.
@@ -1207,7 +1199,7 @@ rewrite lubE -[in LHS]biglub_hull; congr (|_| _); apply neset_ext => /=.
 rewrite eqEsubset; split=> i /=.
 - have /set0P x0 := set1_neq0 x.
   have /set0P y0 := set1_neq0 y.
-  move/(@hull_setU _ _ (necset1 x) (necset1 y) x0 y0).
+  move/(@hull_setU _ _ (set1 x) (set1 y) x0 y0).
   by move=> [a /asboolP ->] [b /asboolP ->] [p ->]; exists p.
 - by case=> p ? <-; exact/mem_hull_setU.
 Qed.