pressing the space bar will lay a line between the two squares.
Repeating either action removes the domino or line.
+Pressing a number key will highlight all occurrences of that
+number. Pressing that number again will clear the highlighting. Up to two
+different numbers can be highlighted at any given time.
+
(All the actions described in \k{common-actions} are also available.)
\H{dominosa-parameters} \I{parameters, for Dominosa}Dominosa parameters