
   for var (start) (stop) [delta]

    perform a loop, with $var as the loop variable. 
    the value of $var runs from (start) to (stop) inclusive, 
    and is incremented by [delta] (1 by default).

    The loop commands are entered until the appropriate "end" is typed;
    if there are nested loops, macro definitions, or logical blocks,
    the correct "end" is used!

    for may be used at the command line, in a macro, or in an input
    file with no ill effects.

    the variable $var may be accessed during the loop execution.  if
    the variable $var is assigned a value beyond (stop) during the
    loop, the loop execution will end.

    See also: macro, if
