diff --git a/coq/ex/indent_plugins.v b/coq/ex/indent_plugins.v
new file mode 100644
index 000000000..b4f926a08
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+++ b/coq/ex/indent_plugins.v
@@ -0,0 +1,107 @@
+(* Needs ext-lib library to compile. *)
+
+Require Import Coq.ZArith.ZArith_base Coq.Strings.Ascii Coq.Strings.String.
+Require Import ExtLib.Data.Monads.StateMonad ExtLib.Structures.Monads.
+Import StringSyntax.
+Open Scope string_scope.
+Section StateGame.
+  
+  Check Ascii.Space.
+
+  Import MonadNotation.
+  Local Open Scope Z_scope.
+  Local Open Scope char_scope.
+  Local Open Scope monad_scope.
+
+  Definition GameValue : Type := Z.
+  Definition GameState : Type := (prod bool Z).
+
+  Variable m : Type -> Type.
+  Context {Monad_m: Monad m}.
+  Context {State_m: MonadState GameState m}.
+
+  Print Grammar constr.
+
+  Fixpoint playGame (s: string) m' {struct s}: m GameValue :=
+    match s with
+    |  EmptyString =>
+       v <- (if true then m' else get) ;;
+       let '(on, score) := v in ret score
+    |  String x xs =>
+       v <- get ;;
+       let '(on, score) := v in
+       match x, on with
+       | "a"%char, true =>  put (on, score + 1)
+       | "b"%char, true => put (on, score - 1)
+       | "c"%char, _ =>   put (negb on, score)
+       |  _, _  =>    put (on, score)
+       end ;;
+       playGame xs m'
+    end.
+
+  Definition startState: GameState := (false, 0).
+
+End StateGame.
+
+(* Needs Equations plugin to work. *)
+
+From Coq Require Import Arith Omega Program.
+From Equations Require Import Equations.
+Require Import Bvector.
+
+
+Module Equations.
+  Equations neg (b : bool) : bool :=
+    neg true := false ;
+    neg false := true.
+
+  Equations neg' (b : bool) : bool :=
+    neg true => false ;
+    neg false => true.
+  
+  Check neg_graph.
+  Check neg_graph_equation_1.
+  Check neg_graph_equation_2.
+
+  Lemma neg_inv : forall b, neg (neg b) = b.
+  Proof.
+    intros b.
+    funelim (neg b); now simp neg.
+  Defined.
+
+
+  Inductive list {A} : Type := nil : list | cons : A -> list -> list.
+
+  Arguments list : clear implicits.
+  Notation "x :: l" := (cons x l). 
+
+  Equations tail {A} (l : list A) : list A :=
+    tail nil :=
+      nil ;
+    tail (cons a v)
+    := v.
+
+  (* The cases inside { } are recognized as record fields, which from
+     an indentation perspective is OK *)
+  Equations filter {A} (l : list A) (p : A -> bool) : list A :=
+    filter (cons a l) p with p a =>
+    { filter (cons a l) p true := a :: filter l p ;
+      filter (cons a l) p false := filter l p
+    };
+    filter nil p := nil 
+  .
+
+  Equations unzip {A B} (l : list (A * B)) : list A * list B :=
+    unzip nil := (nil, nil) ;
+    unzip (cons p l) with unzip l => {
+      unzip (cons (pair a b) l) (pair la lb) := (a :: la, b :: lb) }.
+
+
+  Equations equal (n m : nat) : { n = m } + { n <> m } :=
+    equal O O := left eq_refl ;
+    equal (S n) (S m) with equal n m :=
+    { equal (S n) (S ?(n)) (left eq_refl) := left eq_refl ;
+      equal (S n) (S m) (right p) := right _ } ;
+    equal x y := right _.
+  
+End Equations.