`
The possible directions are those of section 1.6 and
2.6, and the possible targets include all those
discussed above. Actually the direction is only required for the
first in a series of turns since the final direction of one turn is
the obvious choice for the following turn. Furthermore, turns can be
changed from the default by adding either ^d for
anticlockwise turn to d or _d for clockwise turn to d,
where d is the "exit direction" of the turn.
Finally, the turns will have radius 10pt by default, but this
can be changed to any dimension R from a particular turn and
onwards by inserting /R immediately after the " of the
turn. Here is an example involving all of
these features:
\xymatrix{
{\circ} \ar `r[d] ^a
`[rr] ^b
`/4pt[rr] ^c
`[rrr] ^d
`_dl[drrr]^e
[drrr]^f
& {\circ} & {\circ} & {\circ} \\
{\circ} & {\circ} & {\circ} & {\circ} }
typesets

The example illustrates the following points:
` per turn thus each target appears as many
times as there are turns towards it, except the last target that
appears one more time namely both with ` for each turn towards it
and once as an "ordinary" target to set the final stretch.
.