This program demontrates that the tiling system defined in [Rei00]
exactly generates the local language L_S which describes a square, where each corner is surrounded by
a square of half the size.
When started, the program first reads the list of occuring symbols from the input-field.
Each of them is followed by its image (c or d).
Then it reads the vertical and horizontal tiles.
Then it starts to generate the pre-image at the upper left corner.
If the user selcts a field by clicking at it, then the program tries to find a pre-image symbol.
If there is only one choice by considering the neighbors, the image symbol will be replaced,
if there is more then one choice, all possibilities will be shown at the right side of the field
and can be chosen by clicking at it.
If "auto" is activated, the program will automaticly continue row by row (or square by square) until the next unambiguous situation.
If "backtrack" is activated, the program will automaticly try one possibility after the other
and backtrack if the choice can not be continued.
If "back" is activated, clicking at "Go on" leads to the next configuration where it backtracks.
Warning: Activating "backtrack" without clicking at "Start generating" afterwards might cause a too complex task
and the program will not stop voluntarily.
The extraction of all tiles from a picture.
Last modified: 21-Aug-00 by