Alberto Alcalá Alvarez <albertoalcala <at> yahoo.com> writes:
>
> \xymatrix {
> B \ar {-->} [r] & R}
> does something like B>^[r] R
You need an ampersand (@) immediately before the braces:
\xymatrix {B \ar@{-->}[r] & R}
See section 3.4.1 of the XY-pic manual (in the Help menu).
Paul
