If you want spaces around the arrows, put in spaces.
But I'm curious why you don't put the whole thing in some kind of math environment, so the natural "relation spacing" of the arrows kicks in. You could do this, for example, with the align* environment of amsmath. I'm not sure if this is the kind of thing you're after or not, but try:
Code: Select all
\documentclass{book}
\usepackage{amsmath}
\begin{document}
\begin{align*}
\hspace*{4.5cm} \mathrm{A} &\rightarrow 1\\
\mathrm{B} &\rightarrow -1~1\\
\mathrm{C} &\rightarrow -1~0\\
\mathrm{D} &\rightarrow -1~-1\\
\mathrm{E} &\rightarrow 0~1\\
\mathrm{F} &\rightarrow 0~0\\
\mathrm{G} &\rightarrow 0~-1~1\\
\mathrm{H} &\rightarrow 0~-1~0\\
\mathrm{I} &\rightarrow 0~-1~-1\\
\end{align*}
\end{document}
Actually, with what you have, you're not even getting minus signs; you're getting simple hyphens, since they're not in math mode.
Or you might even try a matrix:
Code: Select all
\documentclass{book}
\usepackage{amsmath}
\begin{document}
\hspace*{4.5cm}$\begin{matrix}
\mathrm{A} &\rightarrow &1\\
\mathrm{B} &\rightarrow &-1 &1\\
\mathrm{C} &\rightarrow &-1 &0\\
\mathrm{D} &\rightarrow &-1 &-1\\
\mathrm{E} &\rightarrow &0 &1\\
\mathrm{F} &\rightarrow &0 &0\\
\mathrm{G} &\rightarrow &0 &-1 &1\\
\mathrm{H} &\rightarrow &0 &-1 &0\\
\mathrm{I} &\rightarrow &0 &-1 &-1\\
\end{matrix}
$
\end{document}