fix to nim.efg comment and corresponding documentation in samples.rst

contrib/games/nim.efg

@@ -1,4 +1,4 @@
-EFG 2 R "Nim, starting with Five Stones." { "Player 1" "Player 2" }
+EFG 2 R "Nim-like game, starting with Five Stones, letting players take 1 or 2 Stones in each turn." { "Player 1" "Player 2" }
 
 p "5 left" 1 1 "(1,1)" { "TAKE 1" "TAKE 2" } 0
 p "4 left" 2 1 "(2,1)" { "TAKE 1" "TAKE 2" } 0

doc/samples.rst

@@ -60,10 +60,14 @@ Sample games
   to let you switch doors, should you?
 
 :download:`nim.efg <../contrib/games/nim.efg>`
+  This is a Nim-like game, which is a useful example of the value
+  of backward induction.
+  This version starts with one pile of five stones, and allows the
+  two players to alternately take 1 or 2 stones.
   The classic game of
-  `Nim <http://en.wikipedia.org/wiki/Nim>`_, which is a useful example
-  of the value of backward induction. This version starts with five
-  stones.  An interesting experimental study of this class of games is
+  `Nim <http://en.wikipedia.org/wiki/Nim>`_ allows multiple piles,
+  and allows a player to remove any number of stones from a pile.
+  An interesting experimental study of Nim games is
   `McKinney, C. Nicholas and Van Huyck, John B. (2013) Eureka
   learning: Heuristics and response time in perfect information
   games. Games and Economic Behavior 79: