X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/blobdiff_plain/390cfad8fccd779eef64566015d891efc7d98d15..2e77248ab194f9b38fb25be575070369113ece77:/puzzles.but

diff --git a/puzzles.but b/puzzles.but
index a6d2ef2..4e67a2a 100644
--- a/puzzles.but
+++ b/puzzles.but
@@ -875,12 +875,18 @@ additional digits will be letters of the alphabet. For example, if
 you select 3\by\.4 then the digits which go in your grid will be 1
 to 9, plus \cq{a}, \cq{b} and \cq{c}.
 
-I first saw this puzzle in \i{Nikoli} \k{nikoli-solo}, although it's also
-been popularised by various newspapers under the name \q{\i{Sudoku}} or
-\q{Su Doku}.
+I first saw this puzzle in \i{Nikoli} \k{nikoli-solo}, although it's
+also been popularised by various newspapers under the name
+\q{Sudoku} or \q{Su Doku}.  Howard Garns is considered the inventor
+of the modern form of the puzzle, and it was first published in
+\e{Dell Pencil Puzzles and Word Games}.  A more elaborate treatment
+of the history of the puzzle can be found on Wikipedia
+\k{wikipedia-solo}.
 
 \B{nikoli-solo} \W{http://www.nikoli.co.jp/puzzles/1/index_text-e.htm}\cw{http://www.nikoli.co.jp/puzzles/1/index_text-e.htm}
 
+\B{wikipedia-solo} \W{http://en.wikipedia.org/wiki/Sudoku}\cw{http://en.wikipedia.org/wiki/Sudoku}
+
 \H{solo-controls} \I{controls, for Solo}Solo controls
 
 To play Solo, simply click the mouse in any empty square and then
@@ -1801,20 +1807,11 @@ These parameters are available from the \q{Custom...} option on the
 
 \dd Size of grid in squares.
 
-\dt \e{Recursion depth}
-
-\dd Determines how much guesswork and backtracking you will need to
-do to solve the puzzle. When this is set to zero (as it is for all
-of the \q{Easy} options in the menu), you should always be able to
-deduce the state of an edge without having to guess. If you increase
-it, you will have to guess more and more.
-
-\lcont{
-
-Setting a high value for this option is liable to consume a lot of
-CPU time and memory. Be warned!
+\dt \e{Difficulty}
 
-}
+\dd Controls the difficulty of the generated puzzle.
+\#{FIXME: what distinguishes Easy, Medium, and Hard? In particular,
+when are backtracking/guesswork required, if ever?}
 
 
 \C{inertia} \i{Inertia}