diff --git a/book/30-schema-design/035-diagrams.ipynb b/book/30-schema-design/035-diagrams.ipynb
index 024385a..16ea48a 100644
--- a/book/30-schema-design/035-diagrams.ipynb
+++ b/book/30-schema-design/035-diagrams.ipynb
@@ -4,1214 +4,11 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Diagrams"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Referential integrity\n",
-    "\n",
-    "* Correcting matching of corresponding entities across the schema\n",
-    "* Relies on entity integrity\n",
-    "* Enfornced by foreign keys\n",
-    "\n",
-    "## Foreign keys\n",
-    "A foreign key is a column or several columns in the child table referencing the primary key column(s) in the parent table.\n",
-    "\n",
-    "* More generally, foreign keys can reference other sets of columns than the primary key. However, in common practice and in this class foreign keys will always reference the primary key in the referenced table.\n",
+    "# Diagrams\n",
     "\n",
     "\n",
-    "## Effects of a foreign key constraint\n",
-    "1. Restrict inserts into the child table if there is no match in parent.\n",
-    "2. Restrict deletes (and updates of primary key values) from the parent table when there is a match in child.\n",
-    "3. An index is created in the child table to speed up searches on the foreign key.\n",
-    "\n",
-    "As a result, the child table is prevented from having values in its foreign keys columns in the absence of entries in the parent table with matching primary key values.\n",
-    "\n",
-    "Importantly, unlike other types of links in other data models, no actual link is created between individual rows of both tables. Referential integrity is maintained by restricting dta manipulations."
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Diagramming notation \n",
-    "\n",
-    "- Entity-relationship diagram"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Examples"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stderr",
-     "output_type": "stream",
-     "text": [
-      "[2023-09-12 23:54:22,515][INFO]: Connecting root@fakeservices.datajoint.io:3306\n",
-      "[2023-09-12 23:54:22,522][INFO]: Connected root@fakeservices.datajoint.io:3306\n"
-     ]
-    }
-   ],
-   "source": [
-    "import datajoint as dj\n",
-    "\n",
-    "schema = dj.Schema('person')"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema\n",
-    "class Title(dj.Lookup):\n",
-    "    definition = \"\"\"\n",
-    "    title_code  : char(8)\n",
-    "    ---\n",
-    "    full_title : varchar(120)\n",
-    "    \"\"\"\n",
-    "    \n",
-    "    contents = [\n",
-    "        (\"SW-Dev1\", \"Software Developer 1\"),\n",
-    "        (\"SW-Dev2\", \"Software Developer 2\"),\n",
-    "        (\"SW-Dev3\", \"Software Developer 3\"),\n",
-    "        (\"Web-Dev1\", \"Web Developer 1\"),\n",
-    "        (\"Web-Dev2\", \"Web Developer 2\"),\n",
-    "        (\"Web-Dev3\", \"Web Developer 3\"),\n",
-    "        (\"HR-Mgr\", \"Human Resources Manager\")\n",
-    "    ]"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    <b></b>\n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">title_code</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">full_title</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr> <td>HR-Mgr</td>\n",
-       "<td>Human Resources Manager</td></tr><tr><td>SW-Dev1</td>\n",
-       "<td>Software Developer 1</td></tr><tr><td>SW-Dev2</td>\n",
-       "<td>Software Developer 2</td></tr><tr><td>SW-Dev3</td>\n",
-       "<td>Software Developer 3</td></tr><tr><td>Web-Dev1</td>\n",
-       "<td>Web Developer 1</td></tr><tr><td>Web-Dev2</td>\n",
-       "<td>Web Developer 2</td></tr><tr><td>Web-Dev3</td>\n",
-       "<td>Web Developer 3</td> </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 7</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*title_code    full_title    \n",
-       "+------------+ +------------+\n",
-       "HR-Mgr         Human Resource\n",
-       "SW-Dev1        Software Devel\n",
-       "SW-Dev2        Software Devel\n",
-       "SW-Dev3        Software Devel\n",
-       "Web-Dev1       Web Developer \n",
-       "Web-Dev2       Web Developer \n",
-       "Web-Dev3       Web Developer \n",
-       " (Total: 7)"
-      ]
-     },
-     "execution_count": 3,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "Title()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema\n",
-    "class Person(dj.Manual):\n",
-    "    definition = \"\"\"\n",
-    "    person_id  :  int \n",
-    "    ---\n",
-    "    first_name : varchar(30)\n",
-    "    last_name : varchar(30)\n",
-    "    \"\"\""
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "image/svg+xml": [
-       "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"116pt\" height=\"43pt\" viewBox=\"0.00 0.00 116.00 43.00\">\n",
-       "<g id=\"graph0\" class=\"graph\" transform=\"scale(1 1) rotate(0) translate(4 39)\">\n",
-       "<title>%3</title>\n",
-       "<polygon fill=\"white\" stroke=\"transparent\" points=\"-4,4 -4,-39 112,-39 112,4 -4,4\"/>\n",
-       "<!-- Title -->\n",
-       "<g id=\"node1\" class=\"node\">\n",
-       "<title>Title</title>\n",
-       "<g id=\"a_node1\"><a xlink:title=\"title_code           \r------------------------------\rfull_title           \r\">\n",
-       "<polygon fill=\"#000000\" fill-opacity=\"0.125490\" stroke=\"transparent\" points=\"35,-35 0,-35 0,0 35,0 35,-35\"/>\n",
-       "<text text-anchor=\"start\" x=\"8\" y=\"-16\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"10.00\">Title</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Person -->\n",
-       "<g id=\"node2\" class=\"node\">\n",
-       "<title>Person</title>\n",
-       "<g id=\"a_node2\"><a xlink:title=\"person_id            \r------------------------------\rfirst_name           \rlast_name            \r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"108,-35 53,-35 53,0 108,0 108,-35\"/>\n",
-       "<text text-anchor=\"start\" x=\"61\" y=\"-15.4\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"12.00\" fill=\"darkgreen\">Person</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "</g>\n",
-       "</svg>"
-      ],
-      "text/plain": [
-       "<datajoint.diagram.Diagram at 0x7f66c653d9a0>"
-      ]
-     },
-     "execution_count": 5,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "dj.Diagram(schema)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "Person.insert1((1, \"Bob\", \"Builder\"))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema\n",
-    "class Department(dj.Lookup):\n",
-    "    definition = \"\"\"\n",
-    "    dept_code : char(4) \n",
-    "    --- \n",
-    "    dept_name : varchar(200)   \n",
-    "    \"\"\"\n",
-    "\n",
-    "    contents = (\n",
-    "        (\"BIOL\", \"Biology\"),\n",
-    "        (\"MATH\", \"Mathematics\"),\n",
-    "        (\"STAT\", \"Statistics\"),\n",
-    "        (\"ENG\", \"English\")\n",
-    "        )"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema\n",
-    "class Student(dj.Manual):\n",
-    "    definition = \"\"\"\n",
-    "    -> Person\n",
-    "    ---\n",
-    "    -> Department\n",
-    "    \"\"\""
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema\n",
-    "class Employee(dj.Manual):\n",
-    "    definition = \"\"\"\n",
-    "    -> Person\n",
-    "    ---\n",
-    "    -> Title\n",
-    "    \"\"\""
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 10,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "image/svg+xml": [
-       "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"206pt\" height=\"114pt\" viewBox=\"0.00 0.00 205.50 114.00\">\n",
-       "<g id=\"graph0\" class=\"graph\" transform=\"scale(1 1) rotate(0) translate(4 110)\">\n",
-       "<title>%3</title>\n",
-       "<polygon fill=\"white\" stroke=\"transparent\" points=\"-4,4 -4,-110 201.5,-110 201.5,4 -4,4\"/>\n",
-       "<!-- Department -->\n",
-       "<g id=\"node1\" class=\"node\">\n",
-       "<title>Department</title>\n",
-       "<g id=\"a_node1\"><a xlink:title=\"dept_code            \r------------------------------\rdept_name            \r\">\n",
-       "<polygon fill=\"#000000\" fill-opacity=\"0.125490\" stroke=\"transparent\" points=\"68,-106 0,-106 0,-71 68,-71 68,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"8\" y=\"-87\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"10.00\">Department</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Student -->\n",
-       "<g id=\"node3\" class=\"node\">\n",
-       "<title>Student</title>\n",
-       "<g id=\"a_node3\"><a xlink:title=\"→ Person\r------------------------------\r→ Department\r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"93,-35 35,-35 35,0 93,0 93,-35\"/>\n",
-       "<text text-anchor=\"middle\" x=\"64\" y=\"-14.4\" font-family=\"arial\" font-size=\"12.00\" fill=\"darkgreen\">Student</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Department&#45;&gt;Student -->\n",
-       "<g id=\"edge1\" class=\"edge\">\n",
-       "<title>Department-&gt;Student</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"0.75\" stroke-dasharray=\"5,2\" stroke-opacity=\"0.250980\" d=\"M41.26,-70.8C45.98,-59.95 52.1,-45.87 56.8,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- Employee -->\n",
-       "<g id=\"node2\" class=\"node\">\n",
-       "<title>Employee</title>\n",
-       "<g id=\"a_node2\"><a xlink:title=\"→ Person\r------------------------------\r→ Title\r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"197.5,-35 126.5,-35 126.5,0 197.5,0 197.5,-35\"/>\n",
-       "<text text-anchor=\"middle\" x=\"162\" y=\"-14.4\" font-family=\"arial\" font-size=\"12.00\" fill=\"darkgreen\">Employee</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Title -->\n",
-       "<g id=\"node4\" class=\"node\">\n",
-       "<title>Title</title>\n",
-       "<g id=\"a_node4\"><a xlink:title=\"title_code           \r------------------------------\rfull_title           \r\">\n",
-       "<polygon fill=\"#000000\" fill-opacity=\"0.125490\" stroke=\"transparent\" points=\"194.5,-106 159.5,-106 159.5,-71 194.5,-71 194.5,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"167.5\" y=\"-87\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"10.00\">Title</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Title&#45;&gt;Employee -->\n",
-       "<g id=\"edge2\" class=\"edge\">\n",
-       "<title>Title-&gt;Employee</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"0.75\" stroke-dasharray=\"5,2\" stroke-opacity=\"0.250980\" d=\"M173.37,-70.8C171.01,-59.95 167.95,-45.87 165.6,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- Person -->\n",
-       "<g id=\"node5\" class=\"node\">\n",
-       "<title>Person</title>\n",
-       "<g id=\"a_node5\"><a xlink:title=\"person_id            \r------------------------------\rfirst_name           \rlast_name            \r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"141.5,-106 86.5,-106 86.5,-71 141.5,-71 141.5,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"94.5\" y=\"-86.4\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"12.00\" fill=\"darkgreen\">Person</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Person&#45;&gt;Employee -->\n",
-       "<g id=\"edge3\" class=\"edge\">\n",
-       "<title>Person-&gt;Employee</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" stroke-opacity=\"0.250980\" d=\"M125.62,-70.8C133.17,-59.95 142.96,-45.87 150.49,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- Person&#45;&gt;Student -->\n",
-       "<g id=\"edge4\" class=\"edge\">\n",
-       "<title>Person-&gt;Student</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" stroke-opacity=\"0.250980\" d=\"M101.9,-70.8C94.04,-59.95 83.83,-45.87 75.99,-35.05\"/>\n",
-       "</g>\n",
-       "</g>\n",
-       "</svg>"
-      ],
-      "text/plain": [
-       "<datajoint.diagram.Diagram at 0x7f66c65e8e80>"
-      ]
-     },
-     "execution_count": 10,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "dj.Diagram(schema)"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Foreign keys have 4 effects\n",
-    "0. The primary key of the parent becomes part of the child definition (the foreign key)\n",
-    "1. Restrict inserts into child table if no match in parent\n",
-    "2. Restrict deletes from parent if there is a matching child \n",
-    "3. Create an index in child to make searches fast on the value of the FK value."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    <b></b>\n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">dept_code</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">dept_name</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr> <td>BIOL</td>\n",
-       "<td>Biology</td></tr><tr><td>ENG</td>\n",
-       "<td>English</td></tr><tr><td>MATH</td>\n",
-       "<td>Mathematics</td></tr><tr><td>STAT</td>\n",
-       "<td>Statistics</td> </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 4</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*dept_code    dept_name     \n",
-       "+-----------+ +------------+\n",
-       "BIOL          Biology       \n",
-       "ENG           English       \n",
-       "MATH          Mathematics   \n",
-       "STAT          Statistics    \n",
-       " (Total: 4)"
-      ]
-     },
-     "execution_count": 11,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "Department()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    <b></b>\n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">person_id</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">dept_code</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr>  </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 0</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*person_id    dept_code    \n",
-       "+-----------+ +-----------+\n",
-       "\n",
-       " (Total: 0)"
-      ]
-     },
-     "execution_count": 12,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "Student()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    <b></b>\n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">person_id</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">first_name</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">last_name</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr> <td>1</td>\n",
-       "<td>Bob</td>\n",
-       "<td>Builder</td> </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 1</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*person_id    first_name     last_name    \n",
-       "+-----------+ +------------+ +-----------+\n",
-       "1             Bob            Builder      \n",
-       " (Total: 1)"
-      ]
-     },
-     "execution_count": 13,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "Person()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "Student.insert1((1, \"BIOL\"))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema \n",
-    "class Language(dj.Lookup):\n",
-    "    definition = \"\"\"\n",
-    "    lang_code  : char(8)\n",
-    "    ---\n",
-    "    language : varchar(20)\n",
-    "    \"\"\"\n",
-    "    \n",
-    "    contents = [\n",
-    "        (\"Eng\", \"English\"),\n",
-    "        (\"Nav\", \"Navajo\"),\n",
-    "        (\"Fr\", \"French\"),\n",
-    "        (\"It\", \"Italian\"),\n",
-    "        (\"Sp\", \"Spanish\"),\n",
-    "        (\"Ar\", \"Arabic\")        \n",
-    "    ]"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 18,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    <b></b>\n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">lang_code</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">language</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr> <td>Ar</td>\n",
-       "<td>Arabic</td></tr><tr><td>Eng</td>\n",
-       "<td>English</td></tr><tr><td>Fr</td>\n",
-       "<td>French</td></tr><tr><td>It</td>\n",
-       "<td>Italian</td></tr><tr><td>Nav</td>\n",
-       "<td>Navajo</td></tr><tr><td>Sp</td>\n",
-       "<td>Spanish</td> </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 6</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*lang_code    language    \n",
-       "+-----------+ +----------+\n",
-       "Ar            Arabic      \n",
-       "Eng           English     \n",
-       "Fr            French      \n",
-       "It            Italian     \n",
-       "Nav           Navajo      \n",
-       "Sp            Spanish     \n",
-       " (Total: 6)"
-      ]
-     },
-     "execution_count": 18,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "Language()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@schema\n",
-    "class LanguageSkill(dj.Manual):\n",
-    "    definition = \"\"\"\n",
-    "    -> Person\n",
-    "    -> Language\n",
-    "    ---\n",
-    "    skill_level  : enum(\"beginner\", \"intermediate\", \"fluent\", \"native\")\n",
-    "    \"\"\""
+    "Several diagramming notations have been used for designing relational schema, as summarized in <project:../20-concepts/01-relational>"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    <b></b>\n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">person_id</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">lang_code</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">skill_level</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr>  </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 0</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*person_id    *lang_code    skill_level   \n",
-       "+-----------+ +-----------+ +------------+\n",
-       "\n",
-       " (Total: 0)"
-      ]
-     },
-     "execution_count": 19,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "LanguageSkill()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 24,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "LanguageSkill.insert1((1, \"Sp\", \"fluent\"))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 26,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/html": [
-       "\n",
-       "    \n",
-       "    <style type=\"text/css\">\n",
-       "        .Table{\n",
-       "            border-collapse:collapse;\n",
-       "        }\n",
-       "        .Table th{\n",
-       "            background: #A0A0A0; color: #ffffff; padding:4px; border:#f0e0e0 1px solid;\n",
-       "            font-weight: normal; font-family: monospace; font-size: 100%;\n",
-       "        }\n",
-       "        .Table td{\n",
-       "            padding:4px; border:#f0e0e0 1px solid; font-size:100%;\n",
-       "        }\n",
-       "        .Table tr:nth-child(odd){\n",
-       "            background: #ffffff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        .Table tr:nth-child(even){\n",
-       "            background: #f3f1ff;\n",
-       "            color: #000000;\n",
-       "        }\n",
-       "        /* Tooltip container */\n",
-       "        .djtooltip {\n",
-       "        }\n",
-       "        /* Tooltip text */\n",
-       "        .djtooltip .djtooltiptext {\n",
-       "            visibility: hidden;\n",
-       "            width: 120px;\n",
-       "            background-color: black;\n",
-       "            color: #fff;\n",
-       "            text-align: center;\n",
-       "            padding: 5px 0;\n",
-       "            border-radius: 6px;\n",
-       "            /* Position the tooltip text - see examples below! */\n",
-       "            position: absolute;\n",
-       "            z-index: 1;\n",
-       "        }\n",
-       "        #primary {\n",
-       "            font-weight: bold;\n",
-       "            color: black;\n",
-       "        }\n",
-       "        #nonprimary {\n",
-       "            font-weight: normal;\n",
-       "            color: white;\n",
-       "        }\n",
-       "\n",
-       "        /* Show the tooltip text when you mouse over the tooltip container */\n",
-       "        .djtooltip:hover .djtooltiptext {\n",
-       "            visibility: visible;\n",
-       "        }\n",
-       "    </style>\n",
-       "    \n",
-       "    \n",
-       "        <div style=\"max-height:1000px;max-width:1500px;overflow:auto;\">\n",
-       "        <table border=\"1\" class=\"Table\">\n",
-       "            <thead> <tr style=\"text-align: right;\"> <th> <div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">person_id</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"primary\">lang_code</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">skill_level</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">first_name</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">last_name</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div></th><th><div class=\"djtooltip\">\n",
-       "                            <p id=\"nonprimary\">language</p>\n",
-       "                            <span class=\"djtooltiptext\"></span>\n",
-       "                        </div> </th> </tr> </thead>\n",
-       "            <tbody> <tr> <td>1</td>\n",
-       "<td>Eng</td>\n",
-       "<td>beginner</td>\n",
-       "<td>Bob</td>\n",
-       "<td>Builder</td>\n",
-       "<td>English</td></tr><tr><td>1</td>\n",
-       "<td>Sp</td>\n",
-       "<td>fluent</td>\n",
-       "<td>Bob</td>\n",
-       "<td>Builder</td>\n",
-       "<td>Spanish</td> </tr> </tbody>\n",
-       "        </table>\n",
-       "        \n",
-       "        <p>Total: 2</p></div>\n",
-       "        "
-      ],
-      "text/plain": [
-       "*person_id    *lang_code    skill_level    first_name     last_name     language    \n",
-       "+-----------+ +-----------+ +------------+ +------------+ +-----------+ +----------+\n",
-       "1             Eng           beginner       Bob            Builder       English     \n",
-       "1             Sp            fluent         Bob            Builder       Spanish     \n",
-       " (Total: 2)"
-      ]
-     },
-     "execution_count": 26,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "LanguageSkill * Person * Language"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 27,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "image/svg+xml": [
-       "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"294pt\" height=\"114pt\" viewBox=\"0.00 0.00 293.50 114.00\">\n",
-       "<g id=\"graph0\" class=\"graph\" transform=\"scale(1 1) rotate(0) translate(4 110)\">\n",
-       "<title>%3</title>\n",
-       "<polygon fill=\"white\" stroke=\"transparent\" points=\"-4,4 -4,-110 289.5,-110 289.5,4 -4,4\"/>\n",
-       "<!-- Department -->\n",
-       "<g id=\"node1\" class=\"node\">\n",
-       "<title>Department</title>\n",
-       "<g id=\"a_node1\"><a xlink:title=\"dept_code            \r------------------------------\rdept_name            \r\">\n",
-       "<polygon fill=\"#000000\" fill-opacity=\"0.125490\" stroke=\"transparent\" points=\"68,-106 0,-106 0,-71 68,-71 68,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"8\" y=\"-87\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"10.00\">Department</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Student -->\n",
-       "<g id=\"node4\" class=\"node\">\n",
-       "<title>Student</title>\n",
-       "<g id=\"a_node4\"><a xlink:title=\"→ Person\r------------------------------\r→ Department\r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"75,-35 17,-35 17,0 75,0 75,-35\"/>\n",
-       "<text text-anchor=\"middle\" x=\"46\" y=\"-14.4\" font-family=\"arial\" font-size=\"12.00\" fill=\"darkgreen\">Student</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Department&#45;&gt;Student -->\n",
-       "<g id=\"edge1\" class=\"edge\">\n",
-       "<title>Department-&gt;Student</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"0.75\" stroke-dasharray=\"5,2\" stroke-opacity=\"0.250980\" d=\"M36.9,-70.8C38.79,-59.95 41.24,-45.87 43.12,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- LanguageSkill -->\n",
-       "<g id=\"node2\" class=\"node\">\n",
-       "<title>LanguageSkill</title>\n",
-       "<g id=\"a_node2\"><a xlink:title=\"→ Person\r→ Language\r------------------------------\rskill_level          \r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"193,-35 99,-35 99,0 193,0 193,-35\"/>\n",
-       "<text text-anchor=\"middle\" x=\"146\" y=\"-14.4\" font-family=\"arial\" font-size=\"12.00\" fill=\"darkgreen\">LanguageSkill</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Employee -->\n",
-       "<g id=\"node3\" class=\"node\">\n",
-       "<title>Employee</title>\n",
-       "<g id=\"a_node3\"><a xlink:title=\"→ Person\r------------------------------\r→ Title\r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"285.5,-35 214.5,-35 214.5,0 285.5,0 285.5,-35\"/>\n",
-       "<text text-anchor=\"middle\" x=\"250\" y=\"-14.4\" font-family=\"arial\" font-size=\"12.00\" fill=\"darkgreen\">Employee</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Language -->\n",
-       "<g id=\"node5\" class=\"node\">\n",
-       "<title>Language</title>\n",
-       "<g id=\"a_node5\"><a xlink:title=\"lang_code            \r------------------------------\rlanguage             \r\">\n",
-       "<polygon fill=\"#000000\" fill-opacity=\"0.125490\" stroke=\"transparent\" points=\"218.5,-106 159.5,-106 159.5,-71 218.5,-71 218.5,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"167.5\" y=\"-87\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"10.00\">Language</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Language&#45;&gt;LanguageSkill -->\n",
-       "<g id=\"edge2\" class=\"edge\">\n",
-       "<title>Language-&gt;LanguageSkill</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"0.75\" stroke-opacity=\"0.250980\" d=\"M178.59,-70.8C171.83,-59.95 163.05,-45.87 156.31,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- Title -->\n",
-       "<g id=\"node6\" class=\"node\">\n",
-       "<title>Title</title>\n",
-       "<g id=\"a_node6\"><a xlink:title=\"title_code           \r------------------------------\rfull_title           \r\">\n",
-       "<polygon fill=\"#000000\" fill-opacity=\"0.125490\" stroke=\"transparent\" points=\"271.5,-106 236.5,-106 236.5,-71 271.5,-71 271.5,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"244.5\" y=\"-87\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"10.00\">Title</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Title&#45;&gt;Employee -->\n",
-       "<g id=\"edge3\" class=\"edge\">\n",
-       "<title>Title-&gt;Employee</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"0.75\" stroke-dasharray=\"5,2\" stroke-opacity=\"0.250980\" d=\"M253.03,-70.8C252.4,-59.95 251.59,-45.87 250.96,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- Person -->\n",
-       "<g id=\"node7\" class=\"node\">\n",
-       "<title>Person</title>\n",
-       "<g id=\"a_node7\"><a xlink:title=\"person_id            \r------------------------------\rfirst_name           \rlast_name            \r\">\n",
-       "<polygon fill=\"#00ff00\" fill-opacity=\"0.188235\" stroke=\"#00ff00\" stroke-opacity=\"0.188235\" points=\"141.5,-106 86.5,-106 86.5,-71 141.5,-71 141.5,-106\"/>\n",
-       "<text text-anchor=\"start\" x=\"94.5\" y=\"-86.4\" font-family=\"arial\" text-decoration=\"underline\" font-size=\"12.00\" fill=\"darkgreen\">Person</text>\n",
-       "</a>\n",
-       "</g>\n",
-       "</g>\n",
-       "<!-- Person&#45;&gt;LanguageSkill -->\n",
-       "<g id=\"edge4\" class=\"edge\">\n",
-       "<title>Person-&gt;LanguageSkill</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"0.75\" stroke-opacity=\"0.250980\" d=\"M121.75,-70.8C126.78,-59.95 133.31,-45.87 138.33,-35.05\"/>\n",
-       "</g>\n",
-       "<!-- Person&#45;&gt;Employee -->\n",
-       "<g id=\"edge5\" class=\"edge\">\n",
-       "<title>Person-&gt;Employee</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" stroke-opacity=\"0.250980\" d=\"M141.52,-73.54C163.41,-62.43 194.09,-46.86 217.25,-35.12\"/>\n",
-       "</g>\n",
-       "<!-- Person&#45;&gt;Student -->\n",
-       "<g id=\"edge6\" class=\"edge\">\n",
-       "<title>Person-&gt;Student</title>\n",
-       "<path fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" stroke-opacity=\"0.250980\" d=\"M97.54,-70.8C86.85,-59.95 72.97,-45.87 62.31,-35.05\"/>\n",
-       "</g>\n",
-       "</g>\n",
-       "</svg>"
-      ],
-      "text/plain": [
-       "<datajoint.diagram.Diagram at 0x7f66c5a1bfd0>"
-      ]
-     },
-     "execution_count": 27,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "dj.Diagram(schema)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {