Following is a demo of the blocks.pl program, Task 2.
?- talktome.
Currently...
the large yellow block is on the table
the large red block is on the table
the large blue block is on the table
the large green block is on the table
the small yellow block is on the table
the small red block is on the table
the small blue block is on the table
the small green block is on the table
What would you like to do next?
|: pickup the red block.
Reference resolution error. Try again.
What would you like to do next?
|: stack the small red block on the small yellow block
Currently...
the large yellow block is on the table
the large red block is on the table
the large blue block is on the table
the large green block is on the table
the small yellow block is on the table
the small red block is on the small yellow block
the small blue block is on the table
the small green block is on the table
What would you like to do next?
|: stack the large yellow block on the large green block
Currently...
the large yellow block is on the large green block
the large red block is on the table
the large blue block is on the table
the large green block is on the table
the small yellow block is on the table
the small red block is on the small yellow block
the small blue block is on the table
the small green block is on the table
What would you like to do next?
|: pickup the red block from the yellow block
Currently...
the large yellow block is on the large green block
the large red block is on the table
the large blue block is on the table
the large green block is on the table
the small yellow block is on the table
the small red block is in the hand
the small blue block is on the table
the small green block is on the table
What would you like to do next?
|: exit
false.