Following is a demo of the ? program.
?- 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 large red block. Currently... the large yellow block is on the table the large red block is in the hand 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 large red block. Reference resolution error. Try again. What would you like to do next? |: exit false.