21 Commands for Fixing Typos
In this chapter we describe the commands that are especially useful for
the times when you catch a mistake in your text just after you have made
it, or change your mind while composing text on the fly.
The most fundamental command for correcting erroneous editing is the
undo command, C-x u or C-_ or C-/. This command
undoes a single command (usually), a part of a command (in the case of
query-replace), or several consecutive self-inserting
characters. Consecutive repetitions of the undo command undo earlier
and earlier changes, back to the limit of the undo information
available. See Undo, for more information.