diff --git a/mathematical/TransitiveClosure.ipynb b/mathematical/TransitiveClosure.ipynb
index 9ef3b035c97fd8f767cec95ae284f8affb3045f7..e97f94c614ee62cea5debf8e9e7043c03ee65fd2 100644
--- a/mathematical/TransitiveClosure.ipynb
+++ b/mathematical/TransitiveClosure.ipynb
@@ -512,7 +512,9 @@
     "\n",
     "Transitive closure can actually not be axiomatised in first-order logic.\n",
     "As B is based on first-order logic, can we do this without resorting to the built-in operator ```closure1```?\n",
-    "The answer is yes, becase B has higher-order values and we can arbitrarily quantify over sets and relation values."
+    "The answer is yes, because B has higher-order values and we can arbitrarily quantify over sets and relation values.\n",
+    "We have to specify that all other relations contained in cls1 are not a solution.\n",
+    "With this we get a single solution, encoding our expected transitive closure of the next relation:"
    ]
   },
   {
@@ -655,6 +657,7 @@
    "id": "6142e45d",
    "metadata": {},
    "source": [
+    "## Digression: Encoding transitive closure in Prolog\n",
     "In Prolog we can encode transitive closure as this:\n",
     "```\n",
     "cls1(A,B) :- next(A,B).\n",