box to rename
the operator to "move".</tt></li>

<li>
<tt>Click on the radio button "Add Necessary", then select the state "at_bag(Bag,Place)"
from the substate list window. Click on the canvas, the left hand side
statement of the necessary condition will appear on the canvas as a gray
round rectangle, in the meantime, the right hand side statement appears
as an empty round rectangle with flashing edges waiting for the user's
input (Figure 7). The content of "Substate List" window has been updated
to the st