diff --git a/sandbox/plt1.ipynb b/sandbox/plt1.ipynb
deleted file mode 100644
index ed7b0a7..0000000
--- a/sandbox/plt1.ipynb
+++ /dev/null
@@ -1,105 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "id": "3f15cbbc",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "using Plots"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 23,
-   "id": "1d0ff64d",
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "200.0000000000001"
-      ]
-     },
-     "execution_count": 23,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "x = range(1, 2, length=2)\n",
-    "x = x .* 10 .|> log |> sum |> exp\n",
-    "x "
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "id": "1a8dbc43",
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "3-element Array{Float64,1}:\n",
-       "  0.0\n",
-       "  5.0\n",
-       " 10.0"
-      ]
-     },
-     "execution_count": 11,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "collect(x .* 10)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 27,
-   "id": "7e4d8f47",
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "(-Inf, -921.0340371976182)"
-      ]
-     },
-     "execution_count": 27,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "log(0.01^200), 200 * log(0.01)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "9cf526b3",
-   "metadata": {},
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Julia 1.5.3",
-   "language": "julia",
-   "name": "julia-1.5"
-  },
-  "language_info": {
-   "file_extension": ".jl",
-   "mimetype": "application/julia",
-   "name": "julia",
-   "version": "1.5.3"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 5
-}