diff --git a/Categories.Category.Monoidal.Braided.Properties.html b/Categories.Category.Monoidal.Braided.Properties.html
index 3af9ff746..0599f8801 100644
--- a/Categories.Category.Monoidal.Braided.Properties.html
+++ b/Categories.Category.Monoidal.Braided.Properties.html
@@ -157,4 +157,24 @@
≈ λ⇒
⟩
inv-braiding-coherence = ⟺ (switch-fromtoʳ σ braiding-coherence)
+
+
+
+assoc-reverse : [ X ⊗₀ (Y ⊗₀ Z) ⇒ (X ⊗₀ Y) ⊗₀ Z ]⟨
+ id ⊗₁ σ⇒ ⇒⟨ X ⊗₀ (Z ⊗₀ Y) ⟩
+ σ⇒ ⇒⟨ (Z ⊗₀ Y) ⊗₀ X ⟩
+ α⇒ ⇒⟨ Z ⊗₀ (Y ⊗₀ X) ⟩
+ id ⊗₁ σ⇐ ⇒⟨ Z ⊗₀ (X ⊗₀ Y) ⟩
+ σ⇐
+ ≈ α⇐
+ ⟩
+assoc-reverse = begin
+ σ⇐ ∘ id ⊗₁ σ⇐ ∘ α⇒ ∘ σ⇒ ∘ id ⊗₁ σ⇒ ≈˘⟨ refl⟩∘⟨ assoc²' ⟩
+ σ⇐ ∘ (id ⊗₁ σ⇐ ∘ α⇒ ∘ σ⇒) ∘ id ⊗₁ σ⇒ ≈⟨ refl⟩∘⟨ pushˡ hex₁' ⟩
+ σ⇐ ∘ (α⇒ ∘ σ⇒ ⊗₁ id) ∘ α⇐ ∘ id ⊗₁ σ⇒ ≈⟨ refl⟩∘⟨ pullʳ (sym-assoc ○ hexagon₂) ⟩
+ σ⇐ ∘ α⇒ ∘ (α⇐ ∘ σ⇒) ∘ α⇐ ≈⟨ refl⟩∘⟨ pullˡ (cancelˡ associator.isoʳ) ⟩
+ σ⇐ ∘ σ⇒ ∘ α⇐ ≈⟨ cancelˡ (braiding.iso.isoˡ _) ⟩
+ α⇐ ∎
+ where
+ hex₁' = conjugate-from associator (idᵢ ⊗ᵢ σ) (⟺ (hexagon₁ ○ sym-assoc))