\define{dash} \u2013{-}
+\define{times} \u00D7{*}
+
+\define{divide} \u00F7{/}
+
+\define{minus} \u2212{-}
+
This is a collection of small one-player puzzle games.
\copyright This manual is copyright 2004-2009 Simon Tatham. All rights
grid, through the \q{Type} menu.
+\C{keen} \i{Keen}
+
+\cfg{winhelp-topic}{games.keen}
+
+You have a square grid; each square may contain a digit from 1 to
+the size of the grid. The grid is divided into blocks of varying
+shape and size, with arithmetic clues written in them. Your aim is
+to fully populate the grid with digits such that:
+
+\b Each row contains only one occurrence of each digit
+
+\b Each column contains only one occurrence of each digit
+
+\b The digits in each block can be combined to form the number
+stated in the clue, using the arithmetic operation given in the
+clue. That is:
+
+\lcont{
+
+\b An addition clue means that the sum of the digits in the block
+must be the given number. For example, \q{15+} means the contents of
+the block adds up to fifteen.
+
+\b A multiplication clue (e.g. \q{60\times}), similarly, means that
+the product of the digits in the block must be the given number.
+
+\b A subtraction clue will always be written in a block of size two,
+and it means that one of the digits in the block is greater than the
+other by the given amount. For example, \q{2\minus} means that one
+of the digits in the block is 2 more than the other, or equivalently
+that one digit minus the other one is 2. The two digits could be
+either way round, though.
+
+\b A division clue (e.g. \q{3\divide}), similarly, is always in a
+block of size two and means that one digit divided by the other is
+equal to the given amount.
+
+Note that a block may contain more than one digit the same (provided
+the identical ones are not in the same row and column). This rule is
+precisely the opposite of the rule in Solo's \q{Killer} mode (see
+\k{solo}).
+
+}
+
+This puzzle appears in the Times under the name \q{KenKen}.
+
+
+\H{keen-controls} \i{Keen controls}
+
+\IM{Keen controls} controls, for Keen
+
+Keen shares much of its control system with Solo (and Unequal).
+
+To play Keen, simply click the mouse in any empty square and then
+type a digit on the keyboard to fill that square. If you make a
+mistake, click the mouse in the incorrect square and press Space to
+clear it again (or use the Undo feature).
+
+If you \e{right}-click in a square and then type a number, that
+number will be entered in the square as a \q{pencil mark}. You can
+have pencil marks for multiple numbers in the same square. Squares
+containing filled-in numbers cannot also contain pencil marks.
+
+The game pays no attention to pencil marks, so exactly what you use
+them for is up to you: you can use them as reminders that a
+particular square needs to be re-examined once you know more about a
+particular number, or you can use them as lists of the possible
+numbers in a given square, or anything else you feel like.
+
+To erase a single pencil mark, right-click in the square and type
+the same number again.
+
+All pencil marks in a square are erased when you left-click and type
+a number, or when you left-click and press space. Right-clicking and
+pressing space will also erase pencil marks.
+
+As for Solo, the cursor keys can be used in conjunction with the
+digit keys to set numbers or pencil marks. Use the cursor keys to
+move a highlight around the grid, and type a digit to enter it in
+the highlighted square. Pressing return toggles the highlight into a
+mode in which you can enter or remove pencil marks.
+
+Pressing M will fill in a full set of pencil marks in every square
+that does not have a main digit in it.
+
+(All the actions described in \k{common-actions} are also available.)
+
+\H{keen-parameters} \I{parameters, for Keen}Keen parameters
+
+These parameters are available from the \q{Custom...} option on the
+\q{Type} menu.
+
+\dt \e{Grid size}
+
+\dd Specifies the size of the grid. Lower limit is 3; upper limit is
+9 (because the user interface would become more difficult with
+\q{digits} bigger than 9!).
+
+\dt \e{Difficulty}
+
+\dd Controls the difficulty of the generated puzzle. At Unreasonable
+level, some backtracking will be required, but the solution should
+still be unique. The remaining levels require increasingly complex
+reasoning to avoid having to backtrack.
\A{licence} \I{MIT licence}\ii{Licence}
~mdw / sgt / puzzles / blobdiff