A few macros for Barker & Shan-style Tower notation in LaTeX.

Tower.tex

\usepackage{array}
\usepackage{stmaryrd}

% display a one-level tower
\newcommand{\tower}[4][]{%
  \begin{array}{c|c}
    #4 & #3
    \\ \hline
    \multicolumn{2}{c}{#2}
    \\
    \multicolumn{2}{c}{#1}
  \end{array}
}

% display a two-level tower
\newcommand{\multitower}[6][]{%
  \begin{array}{c|c}
    #6 & #5
    \\ \hline
    #4 & #3
    \\ \hline
    \multicolumn{2}{c}{#2}
    \\
    \multicolumn{2}{c}{#1}
  \end{array}
}

% fat slash type notation for a towers---you can keep
% the arguments the same, just add an "un" in front :)
\newcommand{\untower}[4][]{%
  #4 \fatslash (#2 \fatbslash #3)
}
\newcommand{\unmultitower}[6][]{%
  #6 \fatslash ((\untower{#2}{#3}{#4}) \fatbslash #5)
}

% same idea as above, except that it now shows the cps
% translation of the tower (note that you'll have to 
% translate all constituents manually, though).
\newcommand{\cps}[4][]{%
  (#2 \impl #3) \impl #4
}
\newcommand{\multicps}[6][]{%
  ((\cps{#2}{#3}{#4}) \impl #5) \impl #6
}