Some primitives such as prompt-for-key and commands such as EMACS query replace read key-events directly from the keyboard instead of using the command interpreter. To encourage consistency between these commands and to make them portable and easy to customize, there is a mechanism for defining logical key-events.
A logical key-event is a keyword which stands for some set of key-events. The
system globally interprets these key-events as indicators a particular action.
For example, the :help logical key-event represents the set of key-events
that request help in a given Hemlock implementation. This mapping is a
many-to-many mapping, not one-to-one, so a given logical key-event may have
multiple corresponding actual key-events. Also, any key-event may represent
different logical key-events.