I'm not entirely sure I know what you want. Does the following file do it? Paul
#LyX 2.0 created this file. For more info see http://www.lyx.org/ \lyxformat 413 \begin_document \begin_header \textclass article \use_default_options true \maintain_unincluded_children false \language english \language_package default \inputencoding auto \fontencoding global \font_roman default \font_sans default \font_typewriter default \font_default_family default \use_non_tex_fonts false \font_sc false \font_osf false \font_sf_scale 100 \font_tt_scale 100 \graphics default \default_output_format default \output_sync 0 \bibtex_command default \index_command default \paperfontsize default \spacing single \use_hyperref false \papersize letterpaper \use_geometry true \use_amsmath 2 \use_esint 1 \use_mhchem 1 \use_mathdots 1 \cite_engine basic \use_bibtopic false \use_indices false \paperorientation portrait \suppress_date false \use_refstyle 1 \index Index \shortcut idx \color #008000 \end_index \leftmargin 1in \topmargin 1in \rightmargin 1in \bottommargin 1in \secnumdepth 3 \tocdepth 3 \paragraph_separation skip \defskip smallskip \quotes_language english \papercolumns 1 \papersides 1 \paperpagestyle default \tracking_changes false \output_changes false \html_math_output 0 \html_css_as_file 0 \html_be_strict false \end_header \begin_body \begin_layout Standard \begin_inset Formula $\xymatrix{ & & & & S_{0}u^{2}\\ & & S_{0}u\ar[urr]\ar[drr]\\ S_{0}\ar[urr]\ar[drr] & & & & \genfrac{}{}{0pt}{0}{S_{0}u}{f_{u}}\\ & & S_{0}d\ar[urr]\ar[drr]\\ & & & & S_{0}d^{2} } $ \end_inset \end_layout \end_body \end_document
