diff --git a/4-reduction/sciline-introduction.ipynb b/4-reduction/sciline-introduction.ipynb
index 49855978..c13ed49a 100644
--- a/4-reduction/sciline-introduction.ipynb
+++ b/4-reduction/sciline-introduction.ipynb
@@ -92,7 +92,20 @@
"- List of peaks and associated intensities (diffraction).\n",
"- Etc.\n",
"\n",
- "\n"
+ "\n",
+ "\n",
+ "### How does Sciline know how to build the graph?\n",
+ "\n",
+ "Each domain type is **unique**, and given a list of all functions to be used in the workflow,\n",
+ "Sciline can figure out how to connect the nodes in the graph.\n",
+ "\n",
+ "Think of it like puzzle pieces that fit into each other:\n",
+ "\n",
+ "\n",
+ "\n",
+ "