13. 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 left selection mode and the user inputs the second indicator, setting the current selection to a selection of a parent computational construct of the unary operator by applying the second indicator to the parent computational construct.
13. 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 left selection mode and the user inputs the second indicator, setting the current selection to a selection of a parent computational construct of the unary operator by applying the second indicator to the parent computational construct. 14. The method of claim 13 wherein the first indicator is a tab and the second indicator is a shift-tab.