`print-X-axis`

FunctionX axis labels are much like Y axis labels, except that the ticks are on a line above the numbers. Labels should look like this:

| | | | 1 5 10 15

The first tic is under the first column of the graph and is preceded by
several blank spaces. These spaces provide room in rows above for the Y
axis labels. The second, third, fourth, and subsequent ticks are all
spaced equally, according to the value of `X-axis-label-spacing`

.

The second row of the X axis consists of numbers, preceded by several
blank spaces and also separated according to the value of the variable
`X-axis-label-spacing`

.

The value of the variable `X-axis-label-spacing`

should itself be
measured in units of `symbol-width`

, since you may want to change
the width of the symbols that you are using to print the body of the
graph without changing the ways the graph is labelled.