Syntax
where B is the name of a base which may or may not already exist,
The first form of the syntax is the most usual, and consists of the
command followed by a number of element names
If an element name already exists, it is overwritten, and its
expectation in the default expectation store is as given in the ELEMENT: command, or defaults to
zero, with expectations in other stores being set to zero. However, it
adopts the variance and covariance specifications carried by the former
element. To clear the variance and covariance specifications, issue the
XELEMENT: command first.
The remaining forms of the syntax are used to input a list of elements
either interactively or from a specified address on a macro file. As for
the first form of the syntax, optionally the elements may be gathered
into the base B, and expectations may or may not accompany the element
names, with zero expectations being the default. The second form of the
syntax is used for interactively inputting a list of elements. The
remaining forms specify an address where a list of elements may be
found. If the third form of the command is issued, with no channel
number being specified, the channel number is deduced - [B/D] does not
allow duplicate labels. In the fifth form of the syntax, the beginning
of the file associated with the input channel is indicated. In common
with other macro facilities, the channel number can be zero (meaning the
keyboard): a label should not be supplied in this case. The channel and
label specified or implied must exist at the time the command is issued.
An example of the format necessary for the list of elements to be input
is as follows:
@example These are elements with some non-zero expectations
x1, x2=19.3
y1
z1=19.6, z2=20.1, alpha
#
The element list is terminated by the # symbol. This is true also for
interactive input of a list of elements. Suppose that the elements
listed in the example just given are listed on some macro file already
announced to the program. They could now be input to [B/D] and
gathered into the base named xyz by issuing the following command:
are the names of the elements being defined,
are valid equations, L is the name of a
label and 
is a valid input channel number.
, optionally followed by an expectation 
for the
element. Where no expectation is explicitly given, the expectation is
taken to be zero by default. The expectation is for the default
expectation store: the default can be changed by using the e
argument to the CONTROL: command.
The value given for the expectation may be
changed at a later date by using the E: or EXP:
commands. Expectations for this element in other expectation stores
are set to zero.
Optionally, the
elements declared may be gathered into the base named B, which may or
may not already exist. If the base B already exists it is overwritten.
[=E 
[=E