Mapped and Unmapped Elements

Initially, none of the map elements are mapped. The word "mapped" is used as a short-hand expression: for output map elements, it means the map element has a value expression; for input map elements, it means that the map element is referred to in some output map element's value expression.

Mapped elements are shown in bold font, and unmapped elements are shown in normal font. A map element that contains a mapped map element is also shown in bold.