Exercise 17 corrected after rougier#22

Author: lexnekr

100_Numpy_exercises.ipynb

@@ -339,6 +339,7 @@
     "print(np.nan == np.nan)\n",
     "print(np.inf > np.nan)\n",
     "print(np.nan - np.nan)\n",
+	"print(np.nan in set([np.nan]))\n"
     "print(0.3 == 3 * 0.1)"
    ]
   },

100_Numpy_exercises.md

@@ -146,6 +146,7 @@ print(0 * np.nan)
 print(np.nan == np.nan)
 print(np.inf > np.nan)
 print(np.nan - np.nan)
+print(np.nan in set([np.nan]))
 print(0.3 == 3 * 0.1)
 ```
 

100_Numpy_exercises_no_solution.ipynb

@@ -284,6 +284,7 @@
     "np.nan == np.nan\n",
     "np.inf > np.nan\n",
     "np.nan - np.nan\n",
+	"np.nan in set([np.nan])\n",
     "0.3 == 3 * 0.1\n",
     "```"
    ]

100_Numpy_exercises_no_solution.md

@@ -82,6 +82,7 @@ free to open an issue at <https://github.com/rougier/numpy-100>
 np.nan == np.nan
 np.inf > np.nan
 np.nan - np.nan
+np.nan in set([np.nan])
 0.3 == 3 * 0.1
 ```
 

100_Numpy_exercises_with_hint.ipynb

@@ -301,6 +301,7 @@
     "np.nan == np.nan\n",
     "np.inf > np.nan\n",
     "np.nan - np.nan\n",
+	"np.nan in set([np.nan])\n"
     "0.3 == 3 * 0.1\n",
     "```"
    ]

100_Numpy_exercises_with_hint.md

@@ -116,6 +116,7 @@ free to open an issue at <https://github.com/rougier/numpy-100>
 np.nan == np.nan
 np.inf > np.nan
 np.nan - np.nan
+np.nan in set([np.nan])
 0.3 == 3 * 0.1
 ```