## LaTeX forum ⇒ General ⇒ Unable to compile

LaTeX specific issues not fitting into one of the other forums of this category.
DarkCarb
Posts: 1
Joined: Thu Sep 26, 2019 9:21 am

### Unable to compile

Hello, I just downloaded LaTeX and know almost nothing about the language. I am trying to get a document created for something school related. I downloaded LaTeX and did some googling for what I was trying to do but I cant get my code to compile. Basically, I am trying to output a Truth table for an implication statement. Here is what I have so far. Any explanations of how to fix what I have wrong and tips on the formatting of LaTeX would be much appreciated.
\documentclass{article}
\begin{document}
\begin{table}
\begin{tabular}{•}
\begin{array}{|c |c|c|}
p & q & p \implies q\\
\hline
T & T & T
T & F & F
F & T & T
F & F & T
\end{array}

\end{tabular}

\end{document}

This results in the following error:
! LaTeX Error: Illegal character in array arg.

See the LaTeX manual or LaTeX Companion for explanation.
Type H <return> for immediate help.
...

l.4 \begin{tabular}{•}

?

Ijon Tichy
Posts: 191
Joined: Mon Dec 24, 2018 10:12 am
There are several issues with your code (which is unfortunately also not marked as code using either the Code button in the toolbar or the "Select code" feature):
• * is not a valid column declaration for tabular but a multiplier that expects two arguments.
• array needs the math mode
• \implies is undefined without package, that defines it
• The array row ends are missing.
• \begin{table} without \end{table}
Here one possible suggestion to fix all these issues:
\documentclass{article}\usepackage{mathtools}\begin{document}$\begin{array}{|c|c|c|}p & q & p \implies q\\\hlineT & T & T \\T & F & F \\F & T & T \\F & F & T \\\end{array}$\end{document}

I've removed the table environment, because table without \caption mostly does not make sense.

Please read an introduction to LaTeX. You won't become happy with LaTeX without reading at least a short introduction but I would suggest to read a detailed one.

BTW: Vertical rules/lines in tabulars/tables are awful. See the manual of package booktabs for information how to make nice tabulars/tables.