15. The method of claim 9, further comprising: when the current selection is the selection of the computational construct representing the unary operator and its operand in the right selection mode and the user inputs the first indicator, setting the current selection to a selection of a parent computational construct of the unary operator by applying the first indicator to the parent computational construct.
16. The method of claim 15 wherein the first indicator is a tab and the second indicator is a shift-tab.