Unary plus with numbers?

This is driving me nuts...

I need to write out an explicit plus sign, like (q, 1, +1).

But LaTeX just swallows the '+' sign...

\documentclass{article}
\usepackage{amsmath, amssymb, fourier, mathrsfs}
\usepackage{lmodern, fourier}
\usepackage{dcolumn}

\begin{document}

\begin{tabular}{>{$$}l<{$$}*{3}{|>{$$}c<{$$}}}
\multicolumn{1}{c|}{\boldmath$$q$$\unboldmath} &
\multicolumn{1}{c|}{\boldmath$$0$$\unboldmath} &
\multicolumn{1}{c|}{\boldmath$$1$$\unboldmath} &
\multicolumn{1}{c|}{\boldmath$$b$$\unboldmath} \\
\hline
q_0 & (q_0, 0, +1) & (q_0, 1, +1) & (q_1. b, -1) \\
\hline
\end{tabular}
\end{document}

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@Werner have you seen the column specification? it seems to add $$ and then $$ around each entry. To the OP: if you load lmodern before fourier it seems to resolve the issue –  cmhughes Jul 10 '14 at 19:31
@cmhughes, right. Leaving out lmodern does fix this nonsense. Thanks! –  vonbrand Jul 10 '14 at 19:37
The package fourier uses different encodings for math fonts than the standard ones, so it shouldn't be used along other font packages that use OMS or OMX. This doesn't affect stmaryrd and amssymb that use direct calls of the slots for their symbols. –  egreg Jul 10 '14 at 19:50

It is the fourier package that ate your + with that you get the warning

Missing character: There is no   in font lmsy10!


\documentclass{article}
\usepackage{amsmath, amssymb,
%fourier,
mathrsfs
}
\usepackage{lmodern, fourier}
%%% OK
\usepackage{dcolumn}

\begin{document}
\begin{tabular}{>{$$}l<{$$}*{3}{|>{$$}c<{$$}}}
\multicolumn{1}{c|}{\boldmath$$q$$} &
\multicolumn{1}{c|}{\boldmath$$0$$} &
\multicolumn{1}{c|}{\boldmath$$1$$} &
\multicolumn{1}{c|}{\boldmath$$b$$} \\
\hline
q_0 & (q_0, 0, +1) & (q_0, 1, +1) & (q_1. b, -1) \\
\hline
\end{tabular}
\end{document}

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