Xy-pic User's Guide

## 2.5 More targets

The target address can be given in a large number of formats called positions. The full range of possibilities is described in the reference manual [8, fig. 1,]; here is a number of useful ones in addition to the hop format described in section 1.3:

- ??!C[], where r,c are integers, denotes the relative entry found r rows below and c columns to the right of the current entry (the current entry itself is thus `[0,0]`). This always corresponds to a `[`hop`]`, e.g., `[1,2]` is the same as `[drr]` and `[-2,0]` is the same as `[uu]`.
- , where r,c are positive integers, denotes the absolute entry found in the rth row and cth column of the diagram. The top left entry is `"1,1"`.
- , where t' is any target, changes the base entry of the present arrow to t' and then sets the target to t relative to the original base entry. For example,

  >     \xymatrix{ A \\
  >                B & C \ar@<1ex>[ul]
  >                      \ar@<1ex>[ul];[] }

  typesets

  i.e., the second `\ar[ul]` arrow starts at the `[ul]` entry and ends in the current entry.

See section 3.5 for how to use a label as a target.

Xy-pic User's Guide