Fixed pull request #166

notebooks/Reducer.ipynb

@@ -800,7 +800,7 @@
     }
    },
    "source": [
-    "### A Grammmar-Based Reduction Approach\n",
+    "### A Grammar-Based Reduction Approach\n",
     "\n",
     "To reduce inputs with high syntactical complexity, we use another approach: Rather than reducing the input string, we reduce the _tree_ representing its structure.  The general idea is to start with a _derivation tree_ coming from parsing the input, and then _substitute subtrees by smaller subtrees of the same type_.  These alternate subtrees can either come\n",
     "\n",