From 2003f964c7519e3a22631df8b3168fa788a5fd70 Mon Sep 17 00:00:00 2001
From: Peter Norvig <peter.norvig@gmail.com>
Date: Tue, 16 Jun 2020 15:39:47 -0700
Subject: [PATCH] Update README.md

---
 README.md | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 573f71f..5cc3e42 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 
-<div align="right" style="text-align: right"><i>Peter Norvig<br><a href="https://github.com/norvig/pytudes/blob/master/LICENSE">MIT License</a><br>2015-2020</i></div>
+<div align="right" style="text-align:right"><i>Peter Norvig<br><a href="https://github.com/norvig/pytudes/blob/master/LICENSE">MIT License</a><br>2015-2020</i></div>
 
 # pytudes
 
@@ -29,7 +29,7 @@ Some programs are in Jupyter (`.ipynb`) notebooks, some in `.py` files. For each
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Sierpinski.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FSierpinski.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FSierpinski.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Sierpinski.ipynb) | <b><a href="ipynb/Sierpinski.ipynb" title="A surprising appearance of the Sierpinski triangle in a random walk between vertexes">Chaos with Triangles</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Life.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FLife.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FLife.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Life.ipynb) | <b><a href="ipynb/Life.ipynb" title="The cellular automata zero-player game">Conway's Game of Life</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Dice%20Baseball.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FDice%20Baseball.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FDice%20Baseball.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Dice%20Baseball.ipynb) | <b><a href="ipynb/Dice%20Baseball.ipynb" title="Simulating baseball games">Dice Baseball</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FMaze.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FMaze.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) | <b><a href="ipynb/Maze.ipynb" title="Make a maze by generating a random tree superimposed on a grid">Generating Mazes</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FMaze.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FMaze.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) | <b><a href="ipynb/Maze.ipynb" title="Make a maze by generating a random tree superimposed on a grid and solve it.">Generating and Solving Mazes</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/PhotoFocalLengths.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPhotoFocalLengths.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPhotoFocalLengths.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/PhotoFocalLengths.ipynb) | <b><a href="ipynb/PhotoFocalLengths.ipynb" title="Generate charts of what focal lengths were used on a photo trip.">Photo Focal Lengths</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Pickleball.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPickleball.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPickleball.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Pickleball.ipynb) | <b><a href="ipynb/Pickleball.ipynb" title="Scheduling a doubles tournament fairly and efficiently">Pickleball Tournament</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Project%20Euler%20Utils.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FProject%20Euler%20Utils.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FProject%20Euler%20Utils.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Project%20Euler%20Utils.ipynb) | <b><a href="ipynb/Project%20Euler%20Utils.ipynb" title="My utility functions for the Project Euler problems, including `Primes` and `Factors`">Project Euler Utilities</a></b> |
@@ -41,35 +41,37 @@ Some programs are in Jupyter (`.ipynb`) notebooks, some in `.py` files. For each
 
 |Run | Logic and Number Puzzles|
 |--|---|
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Boggle.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FBoggle.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FBoggle.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Boggle.ipynb) | <b><a href="ipynb/Boggle.ipynb" title="Find all the words on a Boggle board; then find a board with a lot of words">Boggle / Inverse Boggle</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/ElementSpelling.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FElementSpelling.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FElementSpelling.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/ElementSpelling.ipynb) | <b><a href="ipynb/ElementSpelling.ipynb" title="Spelling words using the chemical element symbols, like CoIn">Chemical Element Spelling</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Cryptarithmetic.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FCryptarithmetic.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FCryptarithmetic.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Cryptarithmetic.ipynb) | <b><a href="ipynb/Cryptarithmetic.ipynb" title="Substitute digits for letters and make NUM + BER = PLAY">Cryptarithmetic</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Countdown.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FCountdown.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FCountdown.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Countdown.ipynb) | <b><a href="ipynb/Countdown.ipynb" title="Solving the equation 10 _ 9 _ 8 _ 7 _ 6 _ 5 _ 4 _ 3 _ 2 _ 1 = 2016. From an Alex Bellos puzzle">Four 4s, Five 5s, and Countdown to 2016</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Coin%20Flip.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FCoin%20Flip.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FCoin%20Flip.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Coin%20Flip.ipynb) | <b><a href="ipynb/Coin%20Flip.ipynb" title="How to beat the Devil at his own game">The Devil and the Coin Flip Game</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/flipping.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fflipping.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fflipping.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/flipping.ipynb) | <b><a href="ipynb/flipping.ipynb" title="Can you go through a deck of cards, guessing higher or lower correctly for each card?">Flipping Cards: A Guessing Game</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Gesture%20Typing.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FGesture%20Typing.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FGesture%20Typing.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Gesture%20Typing.ipynb) | <b><a href="ipynb/Gesture%20Typing.ipynb" title="What word has the longest path on a gesture-typing smartphone keyboard?">Gesture Typing</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Ghost.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FGhost.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FGhost.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Ghost.ipynb) | <b><a href="ipynb/Ghost.ipynb" title="The word game Ghost (add letters, try to avoid making a word)">Ghost</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/NightKing.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FNightKing.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FNightKing.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/NightKing.ipynb) | <b><a href="ipynb/NightKing.ipynb" title="Investigasting a battle between the army of the dead and the army of the living">How Many Soldiers Do You Need to Beat the Night King?</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Fred%20Buns.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FFred%20Buns.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FFred%20Buns.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Fred%20Buns.ipynb) | <b><a href="ipynb/Fred%20Buns.ipynb" title="A tale of a bicycle combination lock that uses letters instead of digits. Inspired by Bike Snob NYC">Let's Code About Bike Locks</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Socks.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FSocks.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FSocks.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Socks.ipynb) | <b><a href="ipynb/Socks.ipynb" title="What is the probability that you will be able to pair up socks as you randomly pull them out of the dryer?">Pairing Socks</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Portmantout.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPortmantout.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPortmantout.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Portmantout.ipynb) | <b><a href="ipynb/Portmantout.ipynb" title="Find a long word that squishes together a bunch of words">Portmantout Words</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Mean%20Misanthrope%20Density.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FMean%20Misanthrope%20Density.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FMean%20Misanthrope%20Density.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Mean%20Misanthrope%20Density.ipynb) | <b><a href="ipynb/Mean%20Misanthrope%20Density.ipynb" title="How crowded will this neighborhood be, if nobody wants to live next door to anyone else?">The Puzzle of the Misanthropic Neighbors</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Scrabble.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FScrabble.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FScrabble.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Scrabble.ipynb) | <b><a href="ipynb/Scrabble.ipynb" title="Refactoring the Scrabble / Word with Friends game from Udacity 212">Refactoring a Crossword Game Program</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Riddler%20Battle%20Royale.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FRiddler%20Battle%20Royale.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FRiddler%20Battle%20Royale.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Riddler%20Battle%20Royale.ipynb) | <b><a href="ipynb/Riddler%20Battle%20Royale.ipynb" title="A puzzle involving allocating your troops and going up against an opponent">Riddler: Battle Royale</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/RiddlerLottery.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FRiddlerLottery.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FRiddlerLottery.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/RiddlerLottery.ipynb) | <b><a href="ipynb/RiddlerLottery.ipynb" title="Can you find what lottery number tickets these five friends picked?">Riddler Lottery</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/TourDe538.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FTourDe538.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FTourDe538.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/TourDe538.ipynb) | <b><a href="ipynb/TourDe538.ipynb" title="Solve a puzzle involving the best pace for a bicycle race.">Riddler: Tour de 538</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Sicherman%20Dice.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FSicherman%20Dice.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FSicherman%20Dice.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Sicherman%20Dice.ipynb) | <b><a href="ipynb/Sicherman%20Dice.ipynb" title="Find a pair of dice that is like a regular pair of dice, only different">Sicherman Dice</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Golomb-Puzzle.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FGolomb-Puzzle.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FGolomb-Puzzle.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Golomb-Puzzle.ipynb) | <b><a href="ipynb/Golomb-Puzzle.ipynb" title="A Puzzle involving placing rectangles of different sizes inside a square">Sol Golomb's Rectangle Puzzle</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/SpellingBee.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FSpellingBee.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FSpellingBee.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/SpellingBee.ipynb) | <b><a href="ipynb/SpellingBee.ipynb" title="Find the highest-scoring board for the NY Times Spelling Bee puzzle">Spelling Bee</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/PropositionalLogic.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPropositionalLogic.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPropositionalLogic.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/PropositionalLogic.ipynb) | <b><a href="ipynb/PropositionalLogic.ipynb" title="Automatically convert informal English sentences into formal Propositional Logic">Translating English Sentences into Propositional Logic Statements</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FHow%20to%20Do%20Things%20with%20Words.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FHow%20to%20Do%20Things%20with%20Words.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb) | <b><a href="ipynb/How%20to%20Do%20Things%20with%20Words.ipynb" title="Spelling Correction, Secret Codes, Word Segmentation, and more">How to Do Things with Words: NLP in Python</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Cheryl-and-Eve.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FCheryl-and-Eve.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FCheryl-and-Eve.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Cheryl-and-Eve.ipynb) | <b><a href="ipynb/Cheryl-and-Eve.ipynb" title="Inventing new puzzles in the Style of Cheryl's Birthday">When Cheryl Met Eve: A Birthday Story</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Cheryl.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FCheryl.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FCheryl.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Cheryl.ipynb) | <b><a href="ipynb/Cheryl.ipynb" title="Solving the *Cheryl's Birthday* logic puzzle">When is Cheryl's Birthday?</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/pal3.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fpal3.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fpal3.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/pal3.ipynb) | <b><a href="ipynb/pal3.ipynb" title="Searching for a long Panama-style palindrome, this time letter-by-letter">World's Longest Palindrome</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/xkcd1313-part2.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fxkcd1313-part2.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fxkcd1313-part2.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/xkcd1313-part2.ipynb) | <b><a href="ipynb/xkcd1313-part2.ipynb" title="Regex Golf: better, faster, funner. With Stefan Pochmann">xkcd 1313: Regex Golf (Part 2: Infinite Problems)</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/xkcd1313.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fxkcd1313.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fxkcd1313.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/xkcd1313.ipynb) | <b><a href="ipynb/xkcd1313.ipynb" title="Find the smallest regular expression; inspired by Randall Monroe">xkcd 1313: Regex Golf</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/xkcd-Name-Dominoes.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fxkcd-Name-Dominoes.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fxkcd-Name-Dominoes.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/xkcd-Name-Dominoes.ipynb) | <b><a href="ipynb/xkcd-Name-Dominoes.ipynb" title="Lay out dominoes legally; the dominoes have people names, not numbers">xkcd 1970: Name Dominoes</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/xkcd1313-part2.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fxkcd1313-part2.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fxkcd1313-part2.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/xkcd1313-part2.ipynb) | <b><a href="ipynb/xkcd1313-part2.ipynb" title="Regex Golf: better, faster, funner. With Stefan Pochmann.">xkcd 1313: Regex Golf (Part 2: Infinite Problems)</a></b> |
 
+|run|Word Puzzles|
+|---|------------|
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Boggle.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FBoggle.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FBoggle.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Boggle.ipynb) | <b><a href="ipynb/Boggle.ipynb" title="Find all the words on a Boggle board; then find a board with a lot of words">Boggle / Inverse Boggle</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/ElementSpelling.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FElementSpelling.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FElementSpelling.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/ElementSpelling.ipynb) | <b><a href="ipynb/ElementSpelling.ipynb" title="Spelling words using the chemical element symbols, like CoIn">Chemical Element Spelling</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Gesture%20Typing.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FGesture%20Typing.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FGesture%20Typing.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Gesture%20Typing.ipynb) | <b><a href="ipynb/Gesture%20Typing.ipynb" title="What word has the longest path on a gesture-typing smartphone keyboard?">Gesture Typing</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Ghost.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FGhost.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FGhost.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Ghost.ipynb) | <b><a href="ipynb/Ghost.ipynb" title="The word game Ghost (add letters, try to avoid making a word)">Ghost: A Word game</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FHow%20to%20Do%20Things%20with%20Words.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FHow%20to%20Do%20Things%20with%20Words.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb) | <b><a href="ipynb/How%20to%20Do%20Things%20with%20Words.ipynb" title="Spelling Correction, Secret Codes, Word Segmentation, and more">How to Do Things with Words: NLP in Python</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Portmantout.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPortmantout.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPortmantout.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Portmantout.ipynb) | <b><a href="ipynb/Portmantout.ipynb" title="Find a long word that squishes together a bunch of words">Portmantout Words</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Scrabble.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FScrabble.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FScrabble.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Scrabble.ipynb) | <b><a href="ipynb/Scrabble.ipynb" title="Refactoring the Scrabble / Word with Friends game from Udacity 212">Refactoring a Crossword Game Program</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/SpellingBee.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FSpellingBee.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FSpellingBee.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/SpellingBee.ipynb) | <b><a href="ipynb/SpellingBee.ipynb" title="Find the highest-scoring board for the NY Times Spelling Bee puzzle">Spelling Bee</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/PropositionalLogic.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPropositionalLogic.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPropositionalLogic.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/PropositionalLogic.ipynb) | <b><a href="ipynb/PropositionalLogic.ipynb" title="Automatically convert informal English sentences into formal Propositional Logic">Translating English Sentences into Propositional Logic Statements</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/pal3.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fpal3.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fpal3.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/pal3.ipynb) | <b><a href="ipynb/pal3.ipynb" title="Searching for a long Panama-style palindrome, this time letter-by-letter">World's Longest Palindrome</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/xkcd-Name-Dominoes.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2Fxkcd-Name-Dominoes.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2Fxkcd-Name-Dominoes.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/xkcd-Name-Dominoes.ipynb) | <b><a href="ipynb/xkcd-Name-Dominoes.ipynb" title="Lay out dominoes legally; the dominoes have people names, not numbers">xkcd 1970: Name Dominoes</a></b> |
 
 |Run|Math Concepts|
 |--|--|