When editing text, especially structured text, the need occurs to make repeated changes in multiple locations. A common case is renaming a variable. Select and type, select and type. For a small block of code it's fine. A bit tedious, but fine. Banging this out doesn't take a lot of time. However, the number of keystrokes grows linearly. Increasing the number of references to a few dozens already makes the task quite taxing. We want the effort for repeated changes to grow in a non-linear fashion...