diff --git a/formalizations/guarded-cubical/Semantics/MonotoneCombinators.agda b/formalizations/guarded-cubical/Semantics/MonotoneCombinators.agda
index 0071aabfc5ca4d3fdbe6b623cb50278fcbbd6718..efbb8adaf6e029d6e68daea4d20a3cb16da115db 100644
--- a/formalizations/guarded-cubical/Semantics/MonotoneCombinators.agda
+++ b/formalizations/guarded-cubical/Semantics/MonotoneCombinators.agda
@@ -119,11 +119,7 @@ Case' f g = record {
 Case : ⟨ (A ==> C) ==> (B ==> C) ==> ((A ⊎p B) ==> C) ⟩
 Case = {!!}
 
--- Lifting a monotone function functorially
-_~->_ : {A B C D : Poset ℓ ℓ'} ->
-    ⟨ A ==> B ⟩ -> ⟨ C ==> D ⟩ -> ⟨ (B ==> C) ==> (A ==> D) ⟩
-pre ~-> post = {!!}
-  -- λ f -> mCompU post (mCompU f pre)
+
 
 
 
@@ -301,6 +297,12 @@ Comp : (Γ : Poset ℓ ℓ') -> {A B C : Poset ℓ ℓ'} ->
 Comp Γ f g = {!!}
 
 
+-- Lifting a monotone function functorially
+_~->_ : {A B C D : Poset ℓ ℓ'} ->
+    ⟨ A ==> B ⟩ -> ⟨ C ==> D ⟩ -> ⟨ (B ==> C) ==> (A ==> D) ⟩
+pre ~-> post = Curry ((mCompU post App) ∘m (With2nd pre))
+
+
 
 
 module ClockedCombinators (k : Clock) where