% arara: pdflatex

documentclass{article}
usepackage[all,cmtip]{xy}
usepackage{tikz-cd}

begin{document}
[xymatrix@1{
    & \
    ar@{>->}[ur] &
}]
[begin{tikzcd}
    & null \
    nullar[>->]{ur} &
end{tikzcd}]
end{document}