How can we update stock inventory on delete line items using salesforce trigger

using workflow we can update stock inventory when record is created or edited using priorvalue function. How can we update stock inventory when any line items get deleted. Suppose if i have 10 items and I order  5 items then remaining stock is 5 ..then I  delete one item from list. then correcponding Item should be 6 in stock inventory. How can we achieve this functionalty.

How can we update stock inventory on delete line items using salesforce trigger