SYNTAX            : ARG @X REG

RESULTING ARGUMENT: None

FUNCTION          : Copy all characters between the current cursor position
                    and the beginning of the specified number of lines
                    forward into the register immediately following the
                    command.

                    The cursor (and implicitly the value of  . ) is moved to
                    the end of the copied section.

ARGUMENT          : The number of lines forward (backward if negative).

DEFAULT           : 1

NOTE 1            : Short-hand arguments Z and -Z specify all lines up to
                    the end (or beginning) of the buffer.

NOTE 2            : The previous content of the register is lost; its type
                    is set to string.

7.0:
NOTE 3            : To access the register as an array, a subscript can be
                    used.

MATRIX