3 Fill in the grid with numbers from 1 to the grid size, so that every
4 number appears exactly once in each row and column, and so that all
5 the <code><</code> signs represent true inequalities (i.e. the
6 number at the pointed end is smaller than the number at the open end).
8 To place a number, click in a square to select it, then type the
9 number on the keyboard. To erase a number, click to select a square
10 and then press Backspace.
12 Right-click in a square and then type a number to add or remove the
13 number as a pencil mark, indicating numbers that you think
14 <em>might</em> go in that square.