- ??!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*r*th row and*c*th 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,

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

*i.e.*, the second`\ar[ul]`

arrow starts at the`[ul]`

entry and ends in the current entry.

© Kristoffer H. Rose <krisrose@brics.dk> December 19, 1996 / LaTeX2