diff --git a/crack_bridge.ipynb b/crack_bridge.ipynb
deleted file mode 100644
index 1ba3c1fa65d90be84f6d17686a0c9f817cf1d100..0000000000000000000000000000000000000000
--- a/crack_bridge.ipynb
+++ /dev/null
@@ -1,34 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "wooden-studio",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "import bmcs_utils"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "faced-vaccine",
-   "metadata": {},
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "base",
-   "language": "python",
-   "name": "base"
-  },
-  "language_info": {
-   "name": ""
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 5
-}
diff --git a/index.ipynb b/index.ipynb
index aa7f9ff0aead933b6d4be95c7057a81598c456c0..64f3b275771543d6a246330755ccf217c3897ef1 100644
--- a/index.ipynb
+++ b/index.ipynb
@@ -311,4 +311,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
\ No newline at end of file
+}
diff --git a/pull_out/2_3_PO_ESF_RM.ipynb b/pull_out/2_3_PO_ESF_RM.ipynb
index ca203161f3a08feb7a2d5329ad133a4356aacdbf..a1bc548e6f914ffdbe2f32203502ec65879aee43 100644
--- a/pull_out/2_3_PO_ESF_RM.ipynb
+++ b/pull_out/2_3_PO_ESF_RM.ipynb
@@ -789,7 +789,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.2"
+   "version": "3.9.1"
   },
   "toc": {
    "base_numbering": 1,
diff --git a/pull_out/2_4_PO_comparison.ipynb b/pull_out/2_4_PO_comparison.ipynb
index 37a3e4ca842732bd45038a01dfef8b016bd6a147..872a12a44e68630c2858341a2842749f77088472 100644
--- a/pull_out/2_4_PO_comparison.ipynb
+++ b/pull_out/2_4_PO_comparison.ipynb
@@ -1702,7 +1702,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.2"
+   "version": "3.9.1"
   },
   "toc": {
    "base_numbering": 1,
diff --git a/pull_out/2_6_CB_ELF_ELM.ipynb b/pull_out/2_6_CB_ELF_ELM.ipynb
index ca0ced3f38a3fb28ef58122bf07d96a3a4d871f8..95ae95442e3d4875086057dc41de752b60d4cc1e 100644
--- a/pull_out/2_6_CB_ELF_ELM.ipynb
+++ b/pull_out/2_6_CB_ELF_ELM.ipynb
@@ -2508,7 +2508,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.2"
+   "version": "3.9.1"
   },
   "toc": {
    "base_numbering": 1,
diff --git a/tension/fragmentation.ipynb b/tension/fragmentation.ipynb
index 02f1117095a9662acde230401635f34b4acb90bf..8dbab71db0bcc833bb03d9e0777551c537c18c64 100644
--- a/tension/fragmentation.ipynb
+++ b/tension/fragmentation.ipynb
@@ -2,8 +2,8 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 1,
-   "id": "grand-papua",
+   "execution_count": 2,
+   "id": "prime-protocol",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -13,8 +13,8 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
-   "id": "republican-antarctica",
+   "execution_count": 3,
+   "id": "union-agriculture",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -23,14 +23,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
-   "id": "considered-citation",
+   "execution_count": 4,
+   "id": "fallen-frederick",
    "metadata": {},
    "outputs": [
     {
      "data": {
       "application/vnd.jupyter.widget-view+json": {
-       "model_id": "18ea497b4aa24c02b072dc773977e5eb",
+       "model_id": "834752290e104f5586ad7392a14c56ae",
        "version_major": 2,
        "version_minor": 0
       },
@@ -46,100 +46,10 @@
     "pmcm.interact()"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "id": "widespread-microwave",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "from ipytree import Tree"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "id": "later-albert",
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "application/vnd.jupyter.widget-view+json": {
-       "model_id": "9fc9de961ba64cffac50642d0a9da9d0",
-       "version_major": 2,
-       "version_minor": 0
-      },
-      "text/plain": [
-       "Tree()"
-      ]
-     },
-     "metadata": {},
-     "output_type": "display_data"
-    }
-   ],
-   "source": [
-    "Tree()"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "id": "lovely-commissioner",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "import ipyregulartable as rt"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 10,
-   "id": "material-hampshire",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "import numpy as np"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "id": "silent-maryland",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "w = rt.RegularTableWidget(rt.NumpyDataModel(np.random.random((10,10))) )"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "id": "million-carter",
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "application/vnd.jupyter.widget-view+json": {
-       "model_id": "7a85750248e8496d8eed5ebb4fd856b7",
-       "version_major": 2,
-       "version_minor": 0
-      },
-      "text/plain": [
-       "RegularTableWidget()"
-      ]
-     },
-     "metadata": {},
-     "output_type": "display_data"
-    }
-   ],
-   "source": [
-    "w"
-   ]
-  },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "contrary-ferry",
+   "id": "historical-sixth",
    "metadata": {},
    "outputs": [],
    "source": []