diff --git a/sec4.2.ipynb b/sec4.2.ipynb
index f449a5e..c8ef3a8 100644
--- a/sec4.2.ipynb
+++ b/sec4.2.ipynb
@@ -2,7 +2,7 @@
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@@ -16,31 +16,172 @@
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    "id": "7a1ba495-73ac-4710-bab7-edb429ab9628",
    "metadata": {
     "tags": []
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+       "\n",
+       "        <iframe\n",
+       "            width=\"1080\"\n",
+       "            height=\"800\"\n",
+       "            src=\"https://ufal.mff.cuni.cz/~straka/courses/npfl129/2223/demos/mnist_web.html\"\n",
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+       "            allowfullscreen\n",
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    "source": [
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    "id": "a4827f0c",
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    "id": "f28bd167",
    "metadata": {
     "slideshow": {
@@ -48,7 +189,153 @@
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     "tags": []
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+   "id": "d5651fc9-3fcd-4e91-8d3c-04897da1ea02",
+   "metadata": {
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@@ -56,19 +343,7 @@
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+   "id": "318a7308-55ea-43f4-bdee-df614a22f40d",
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