Sliding arrows sideways

??=[arrows.sliding] It is often desirable to have several arrows between two objects. This can be done by sliding either or both arrows sideways by giving the distance as an optional TEX dimension enclosed in |<>|s: it specifies how far `sideways' the arrow should be moved, ,
\begin{code} \diagram A \drto<1ex>^a_{.} \\ & B \ulto<1ex>^b \rto<1ex>^c & C \lto<1ex>^d_{.} \enddiagram \end{code}
will typeset

$\displaystyle \docode$

A positive distance will slide the arrow in the `|^|-direction', , the two arrows above are slid in the direction of the labels a and b, respectively; a negative distance in the `|_|-direction'. The distance |<1ex>| is often appropriate since it corresponds roughly to the height of letters like `x', independently of the used type size.
In "v3" it is also possible to curve arrows and there is special support for 2-cells.