Cancels the execution of a delayed command that was previously scheduled. Id indicates which command should be canceled; it must have been the return value from a previous after (or after idle) command. If the command given by id has already been executed then the after cancel command has no effect.
This command also cancels the execution of a delayed command. The script arguments are concatenated together with space separators (just as in the concat command). If there is a pending command that matches the string, it is cancelled and will never be executed; if no such command is currently pending then the after cancel command has no effect.