diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8bb6ecf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/.ipynb_checkpoints/*.ipynb
diff --git a/arithmetic.ipynb b/arithmetic.ipynb
index cef420d..92a3dd4 100644
--- a/arithmetic.ipynb
+++ b/arithmetic.ipynb
@@ -10,7 +10,6 @@
     "<!-- Author: -->  \n",
     "**С.В. Лемешевский** (email: `sergey.lemeshevsky@gmail.com`), Институт математики НАН Беларуси\n",
     "\n",
-    "Date: **Feb 19, 2020**\n",
     "\n",
     "Язык Python , благодаря наличию огромного количества библиотек для решения\n",
     "разного рода вычислительных задач, является конкурентом таким пакетам как Matlab и\n",
@@ -58,7 +57,10 @@
    "cell_type": "code",
    "execution_count": 1,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -74,11 +76,25 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 4,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "5"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "a = 3\n",
     "b = 2\n",
@@ -96,7 +112,10 @@
    "cell_type": "code",
    "execution_count": 3,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -118,7 +137,10 @@
    "cell_type": "code",
    "execution_count": 4,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -139,7 +161,10 @@
    "cell_type": "code",
    "execution_count": 5,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -163,7 +188,10 @@
    "cell_type": "code",
    "execution_count": 6,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -174,7 +202,10 @@
    "cell_type": "code",
    "execution_count": 7,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -194,7 +225,10 @@
    "cell_type": "code",
    "execution_count": 8,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -205,7 +239,10 @@
    "cell_type": "code",
    "execution_count": 9,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -225,7 +262,10 @@
    "cell_type": "code",
    "execution_count": 10,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -236,7 +276,10 @@
    "cell_type": "code",
    "execution_count": 11,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -256,7 +299,10 @@
    "cell_type": "code",
    "execution_count": 12,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -267,7 +313,10 @@
    "cell_type": "code",
    "execution_count": 13,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -287,7 +336,10 @@
    "cell_type": "code",
    "execution_count": 14,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -298,7 +350,10 @@
    "cell_type": "code",
    "execution_count": 15,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -331,7 +386,10 @@
    "cell_type": "code",
    "execution_count": 16,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -343,7 +401,10 @@
    "cell_type": "code",
    "execution_count": 17,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -363,7 +424,10 @@
    "cell_type": "code",
    "execution_count": 18,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -374,7 +438,10 @@
    "cell_type": "code",
    "execution_count": 19,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -385,7 +452,10 @@
    "cell_type": "code",
    "execution_count": 20,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -396,7 +466,10 @@
    "cell_type": "code",
    "execution_count": 21,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -407,7 +480,10 @@
    "cell_type": "code",
    "execution_count": 22,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -418,7 +494,10 @@
    "cell_type": "code",
    "execution_count": 23,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -436,7 +515,10 @@
    "cell_type": "code",
    "execution_count": 24,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -448,7 +530,10 @@
    "cell_type": "code",
    "execution_count": 25,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -467,7 +552,10 @@
    "cell_type": "code",
    "execution_count": 26,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -494,14 +582,16 @@
    "cell_type": "code",
    "execution_count": 27,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> p = 9\n",
-    ">>> q = 3\n",
-    ">>> p & q\n",
-    "1"
+    "p = 9\n",
+    "q = 3\n",
+    "p & q"
    ]
   },
   {
@@ -515,12 +605,14 @@
    "cell_type": "code",
    "execution_count": 28,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> p | q\n",
-    "11"
+    "p | q"
    ]
   },
   {
@@ -534,15 +626,35 @@
    "cell_type": "code",
    "execution_count": 29,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> p ^ q\n",
-    "10\n",
-    "Инверсия.\n",
-    ">>> ~ p\n",
-    "- 10"
+    "p^q"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "**Инверсия.**"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "~p"
    ]
   },
   {
@@ -554,16 +666,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 30,
+   "execution_count": 31,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> p << 1\n",
-    "18\n",
-    ">>> p >> 1\n",
-    "4"
+    "p<<1"
    ]
   },
   {
@@ -586,15 +698,17 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 31,
+   "execution_count": 32,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> m = 124504\n",
-    ">>> hex(m)\n",
-    "'0x1e658'"
+    "m = 124504\n",
+    "hex(m)"
    ]
   },
   {
@@ -606,14 +720,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 32,
+   "execution_count": 33,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> oct(m)\n",
-    "'0o363130'"
+    "oct(m)"
    ]
   },
   {
@@ -625,14 +741,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 33,
+   "execution_count": 34,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> bin(m)\n",
-    "'0b11110011001011000'"
+    "bin(m)"
    ]
   },
   {
@@ -654,9 +772,12 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 34,
+   "execution_count": 2,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -676,14 +797,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 35,
+   "execution_count": 36,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.ceil( 3.2 )\n",
-    "4"
+    "math.ceil( 3.2 )"
    ]
   },
   {
@@ -697,14 +820,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 36,
+   "execution_count": 37,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.fabs(-7)\n",
-    "7.0"
+    "math.fabs(-7)"
    ]
   },
   {
@@ -718,14 +843,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 37,
+   "execution_count": 38,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.factorial( 5 )\n",
-    "120"
+    "math.factorial(5)"
    ]
   },
   {
@@ -739,14 +866,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 38,
+   "execution_count": 39,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.floor( 3.2 )\n",
-    "3"
+    "math.floor( 3.2 )"
    ]
   },
   {
@@ -759,14 +888,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 39,
+   "execution_count": 40,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.exp( 3 )\n",
-    "20.08553692318766"
+    "math.exp( 3 )"
    ]
   },
   {
@@ -774,12 +905,50 @@
    "metadata": {},
    "source": [
     "**Функция `math.log2(x)`.**\n",
-    "Логарифм по основанию `2`.\n",
-    "\n",
+    "Логарифм по основанию `2`."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "math.log2(8)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     "**Функция `math.log10(x)`.**\n",
     "\n",
-    "Логарифм по основанию 10.\n",
-    "\n",
+    "Логарифм по основанию 10."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "math.log10( 1000 )"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     "**Функция `math.log(x[, base])`.**\n",
     "\n",
     "По умолчанию вычисляет логарифм по основанию `e`, дополнительно можно указать\n",
@@ -788,20 +957,30 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 40,
+   "execution_count": 43,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.log2( 8 )\n",
-    "3.0\n",
-    ">>> math.log10( 1000 )\n",
-    "3.0\n",
-    ">>> math.log( 5 )\n",
-    "1.609437912434100\n",
-    ">>> math.log( 4 , 8 )\n",
-    "0.666666666666666"
+    "math.log(5)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 44,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "math.log()"
    ]
   },
   {
@@ -815,14 +994,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 41,
+   "execution_count": 45,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> math.pow( 3 , 4 )\n",
-    "81.0"
+    "math.pow(3 , 4)"
    ]
   },
   {
@@ -836,14 +1017,27 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 42,
+   "execution_count": 3,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "5.0"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
-    ">>> math.sqrt( 25 )\n",
-    "5.0"
+    "math.sqrt(25)"
    ]
   },
   {
@@ -884,9 +1078,34 @@
     "<!-- doconce-chapter-nickname: \"arithmetic\" -->\n",
     "<!-- End: -->"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
- "metadata": {},
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.1"
+  }
+ },
  "nbformat": 4,
- "nbformat_minor": 2
+ "nbformat_minor": 4
 }
diff --git a/binder/postBuild b/binder/postBuild
new file mode 100644
index 0000000..1c38284
--- /dev/null
+++ b/binder/postBuild
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+# Import the workspace into JupyterLab
+jupyter lab workspaces import binder/workspace.json
\ No newline at end of file
diff --git a/binder/workspace.json b/binder/workspace.json
new file mode 100644
index 0000000..f4cec9b
--- /dev/null
+++ b/binder/workspace.json
@@ -0,0 +1 @@
+{"data":{"layout-restorer:data":{"main":{"dock":{"type":"tab-area","currentIndex":2,"widgets":["notebook:arithmetic.ipynb","notebook:datatype.ipynb","setting-editor:setting-editor"]},"mode":"multiple-document","current":"setting-editor:setting-editor"},"left":{"collapsed":false,"current":"command-palette","widgets":["filebrowser","running-sessions","command-palette","tab-manager","extensionmanager.main-view"]},"right":{"collapsed":true,"widgets":[]}},"file-browser-filebrowser:cwd":{"path":""},"notebook:arithmetic.ipynb":{"data":{"path":"arithmetic.ipynb","factory":"Notebook"}},"notebook:datatype.ipynb":{"data":{"path":"datatype.ipynb","factory":"Notebook"}},"setting-editor:setting-editor":{"data":{}},"@jupyterlab/settingeditor-extension:plugin":{"sizes":[0.19017980636237897,0.809820193637621],"container":{"plugin":"@jupyterlab/notebook-extension:tracker","sizes":[0.5,0.5]}}},"metadata":{"id":"/lab"}}
diff --git a/datatype.ipynb b/datatype.ipynb
index 30af0b8..e4404b7 100644
--- a/datatype.ipynb
+++ b/datatype.ipynb
@@ -56,7 +56,10 @@
    "cell_type": "code",
    "execution_count": 1,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -148,7 +151,10 @@
    "cell_type": "code",
    "execution_count": 2,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -191,7 +197,10 @@
    "cell_type": "code",
    "execution_count": 3,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
@@ -207,104 +216,31 @@
    ]
   },
   {
-   "cell_type": "markdown",
-   "metadata": {},
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
    "source": [
-    "4\n",
-    " \n",
-    "<\n",
-    "<\n",
-    "<\n",
-    "!\n",
-    "!\n",
-    "C\n",
-    "O\n",
-    "D\n",
-    "E\n",
-    "_\n",
-    "B\n",
-    "L\n",
-    "O\n",
-    "C\n",
-    "K\n",
-    " \n",
-    " \n",
-    "p\n",
-    "y\n",
-    "c\n",
-    "o\n",
-    "d"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "5\n",
-    " \n",
-    "<\n",
-    "<\n",
-    "<\n",
-    "!\n",
-    "!\n",
-    "C\n",
-    "O\n",
-    "D\n",
-    "E\n",
-    "_\n",
-    "B\n",
-    "L\n",
-    "O\n",
-    "C\n",
-    "K\n",
-    " \n",
-    " \n",
-    "p\n",
-    "y\n",
-    "c\n",
-    "o\n",
-    "d"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "6\n",
-    " \n",
-    "<\n",
-    "<\n",
-    "<\n",
-    "!\n",
-    "!\n",
-    "C\n",
-    "O\n",
-    "D\n",
-    "E\n",
-    "_\n",
-    "B\n",
-    "L\n",
-    "O\n",
-    "C\n",
-    "K\n",
-    " \n",
-    " \n",
-    "p\n",
-    "y\n",
-    "c\n",
-    "o\n",
-    "d"
+    "keyword.iskeyword( \"try\" )"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 5,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    "False"
+    "keyword.iskeyword( \"b\" )"
    ]
   },
   {
@@ -317,21 +253,47 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 6,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> a = 4\n",
-    ">>> b = 5\n",
-    ">>> id (a)\n",
-    "1829984576\n",
-    ">>> id (b)\n",
-    "1829984592\n",
-    ">>> a = b\n",
-    ">>> id (a)\n",
-    "1829984592"
+    "a = 4\n",
+    "b = 5\n",
+    "id (a)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "id (b)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "a = b\n",
+    "id (a)"
    ]
   },
   {
@@ -356,21 +318,47 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 9,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> a = 10\n",
-    ">>> b = \"hello\"\n",
-    ">>> c = ( 1 , 2 )\n",
-    ">>> type (a)\n",
-    "< class 'int' >\n",
-    ">>> type (b)\n",
-    "< class 'str' >\n",
-    ">>> type (c)\n",
-    "< class 'tuple' >"
+    "a = 10\n",
+    "b = \"hello\"\n",
+    "c = ( 1 , 2 )\n",
+    "type (a)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "type (b)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "type (c)"
    ]
   },
   {
@@ -420,17 +408,31 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 12,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> k = 15\n",
-    ">>> id (k)\n",
-    "1672501744\n",
-    ">>> type (k)\n",
-    "< class 'int' >"
+    "k = 15\n",
+    "id (k)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "type (k)"
    ]
   },
   {
@@ -446,19 +448,46 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 14,
    "metadata": {
-    "collapsed": false
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
    },
    "outputs": [],
    "source": [
-    ">>> a = [ 1 , 2 ]\n",
-    ">>> id (a)\n",
-    "47997336\n",
-    ">>> a[ 1 ] = 3\n",
-    ">>> a\n",
-    "[ 1 , 3 ]\n",
-    ">>> id (a)"
+    "a = [1 ,2]\n",
+    "id (a)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "a[1] = 3\n",
+    "a"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false,
+    "jupyter": {
+     "outputs_hidden": false
+    }
+   },
+   "outputs": [],
+   "source": [
+    "id(a)"
    ]
   },
   {
@@ -489,7 +518,25 @@
    ]
   }
  ],
- "metadata": {},
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.1"
+  }
+ },
  "nbformat": 4,
- "nbformat_minor": 2
+ "nbformat_minor": 4
 }