\aa : Using a map to call TestOne(). When no count (ie. 5\aa) is provided, the only thing interesting is that firstline and lastline are equal to the current line. 5\aa : Like \aa, but this time lastline= firstline+5-1. Thus one can pass a repetition count of sorts to the map. However, one will get an "Invalid range" error within four lines of the end-of-file. \bb : How to pass the optional "!" to a function. Useful for having an alternate behavior associated with a function. \cc : Illustrates the use of -- note that the first argument \ee : \ee map shows how arguments are still available.