Hello. The easiest (and nicest) way to do this is using the tikz package:
in the preamble put
\usepackage{tikz}
and then, wherever you want the tableau, put in a TeX box the following:
\def\land{\wedge}
\def\lor{\vee}
\def\limp{\to}
\begin{tikzpicture}
\node {$\{\neg ((p \lor (p \land q)) \limp p)\}$}
child {node {$\{p \lor (p \land q), \neg p\}$}
child {node {$\{p\}$}}
child {node {$\{p \land q\}$}
child {node {$\{p,q\}$}}}};
\end{tikzpicture}
Note that the structure of the tree depends on the grouping braces { ... }.
On Tue, Oct 22, 2013 at 12:04 PM, William Hanson <whan...@umn.edu> wrote:
> Dear LyX Colleagues,
>
> I'm trying to create tableau proofs, which are branching columns of text,
> as illustrated in the attachment. Examples can also be found in Melvin
> Fitting and Richard Mendelsohn, *First-Order Modal Logic*, Kluwer, 1998.
> Any help will be appreciated.
>
> Bill Hanson
>
--
Ernesto Posse
Modelling and Analysis in Software Engineering
School of Computing
Queen's University - Kingston, Ontario, Canada
