diff --git a/SciLean/Core/FunctionTransformations/RevCDeriv.lean b/SciLean/Core/FunctionTransformations/RevCDeriv.lean
index 69fd49a3..4f1332e5 100644
--- a/SciLean/Core/FunctionTransformations/RevCDeriv.lean
+++ b/SciLean/Core/FunctionTransformations/RevCDeriv.lean
@@ -15,8 +15,12 @@ variable
   (K : Type _) [IsROrC K]
   {X : Type _} [SemiInnerProductSpace K X]
   {Y : Type _} [SemiInnerProductSpace K Y]
+  {Y₁ : Type _} [SemiInnerProductSpace K Y₁]
+  {Y₂ : Type _} [SemiInnerProductSpace K Y₂]
   {Z : Type _} [SemiInnerProductSpace K Z]
+  {W : Type _} [SemiInnerProductSpace K W]
   {ι : Type _} [EnumType ι]
+  {κ : Type _} [EnumType κ]
   {E : ι → Type _} [∀ i, SemiInnerProductSpace K (E i)]
 
 
@@ -213,6 +217,126 @@ by
   funext _; ftrans; ftrans 
   sorry_proof
 
+-- few more specialized rules for function types
+
+theorem revCDeriv.pi_comp_rule_simple
+  (f : Y → Z) (g : X → ι → Y)
+  (hf : HasAdjDiff K f)
+  (hg : ∀ j, HasAdjDiff K (g · j))
+  : (revCDeriv K fun x i => f (g x i))
+    = 
+    fun x => 
+      let ydg := revCDeriv K g x
+      let zdf := revCDeriv K f
+      (fun i => (zdf (ydg.1 i)).1, 
+       fun dz => 
+         let dy := fun i => (zdf (ydg.1 i)).2 (dz i)
+         ydg.2 dy) := 
+by
+  have ⟨_,_⟩ := hf
+  have _ := fun i => (hg i).1
+  have _ := fun i => (hg i).2
+  unfold revCDeriv
+  funext _; ftrans -- ftrans - semiAdjoint.pi_rule fails because of some universe issues
+  simp
+  sorry_proof
+
+
+theorem revCDeriv.pi_comp_rule
+  (f : Y → ι → Z) (g : X → ι → Y)
+  (hf : ∀ i, HasAdjDiff K (f · i))
+  (hg : ∀ j, HasAdjDiff K (g · j))
+  : (revCDeriv K fun x i => f (g x i) i)
+    = 
+    fun x => 
+      let ydg := revCDeriv K g x
+      let zdf := revCDeriv K (fun (y : ι → Y) i => f (y i) i) ydg.1
+      (zdf.1, 
+       fun dz => 
+         let dy := zdf.2 dz
+         ydg.2 dy) := 
+by
+  have _ := fun i => (hf i).1
+  have _ := fun i => (hf i).2
+  have _ := fun i => (hg i).1
+  have _ := fun i => (hg i).2
+  unfold revCDeriv
+  funext _; ftrans -- ftrans - semiAdjoint.pi_rule fails because of some universe issues
+  simp
+  sorry_proof
+
+theorem revCDeriv.pi_let_rule
+  (f : X → Y → ι → Z) (g : X → ι → Y)
+  (hf : ∀ i, HasAdjDiff K (fun xy : X×Y => f xy.1 xy.2 i))
+  (hg : ∀ j, HasAdjDiff K (g · j))
+  : (revCDeriv K fun x i => let y := g x i; f x y i)
+    = 
+    fun x => 
+      let ydg := revCDeriv K g x
+      let zdf := revCDeriv K (fun (xy : X×(ι →Y)) i => f xy.1 (xy.2 i) i) (x,ydg.1)
+      (zdf.1,
+       fun dz => 
+         let dxy := zdf.2 dz
+         dxy.1 + ydg.2 dxy.2) := 
+by
+  have _ := fun i => (hf i).1
+  have _ := fun i => (hf i).2
+  have _ := fun i => (hg i).1
+  have _ := fun i => (hg i).2
+  unfold revCDeriv
+  funext _; ftrans -- ftrans - semiAdjoint.pi_rule fails because of some universe issues
+  simp
+  sorry_proof
+
+
+theorem revCDeriv.pi_prod_rule
+  (g₁ : W → ι → Y₁) (g₂ : W → ι → Y₂)
+  (hg₁ : ∀ i, HasAdjDiff K (g₁ · i)) (hg₂ : ∀ i, HasAdjDiff K (g₂ · i))
+  : (revCDeriv K fun w i => (g₁ w i, g₂ w i))
+    =
+    fun w => 
+      let ydg₁ := revCDeriv K g₁ w
+      let ydg₂ := revCDeriv K g₂ w
+      (fun i => (ydg₁.1 i, ydg₂.1 i),
+       fun dy => 
+         ydg₁.2 (fun i => (dy i).1) + ydg₂.2 (fun i => (dy i).2)) := 
+by
+  have _ := fun i => (hg₁ i).1
+  have _ := fun i => (hg₁ i).2
+  have _ := fun i => (hg₂ i).1
+  have _ := fun i => (hg₂ i).2
+  unfold revCDeriv
+  funext _; ftrans; -- ftrans - semiAdjoint.pi_rule fails because of some universe issues
+  simp
+  sorry_proof
+
+theorem revCDeriv.pi_uncurry_rule {ι κ} [EnumType ι] [EnumType κ]
+  (f : X → ι → κ → Y) (hf : ∀ i j, HasAdjDiff K (f · i j))
+  : (revCDeriv K fun x i j => f x i j)
+    =
+    fun x =>
+      let ydf := revCDeriv K (fun x' (ij : ι×κ) => f x' ij.1 ij.2) x
+      (fun i j => ydf.1 (i,j), 
+       fun dy => ydf.2 (fun ij : ι×κ => dy ij.1 ij.2)) := 
+by
+  have _ := fun i j => (hf i j).1
+  have _ := fun i j => (hf i j).2
+  unfold revCDeriv 
+  funext _; ftrans; -- ftrans - semiAdjoint.pi_rule fails because of some universe issues
+  simp
+  sorry_proof
+
+
+theorem revCDeriv.pi_curry_rule {ι κ} [EnumType ι] [EnumType κ]
+  (f : X → ι → κ → Y) (hf : ∀ i j, HasAdjDiff K (f · i j))
+  : (revCDeriv K fun x (ij : ι×κ) => f x ij.1 ij.2)
+    =
+    fun x =>
+      let ydf := revCDeriv K (fun x' i j => f x' i j) x
+      (fun ij => ydf.1 ij.1 ij.2, 
+       fun dy => ydf.2 (fun i j => dy (i,j))) := 
+by
+  sorry_proof
 
 
 -- Register `revCDeriv` as function transformation ------------------------------