\begin{tabbing}
RngSig
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=${\it car}$:Type\+
\\[0ex]$\times$ (${\it eq}$:(${\it car}$$\rightarrow$${\it car}$$\rightarrow\mathbb{B}$)
\\[0ex]$\times$ ${\it le}$:(${\it car}$$\rightarrow$${\it car}$$\rightarrow\mathbb{B}$)
\\[0ex]$\times$ ${\it plus}$:(${\it car}$$\rightarrow$${\it car}$$\rightarrow$${\it car}$)
\\[0ex]$\times$ ${\it zero}$:${\it car}$
\\[0ex]$\times$ ${\it minus}$:(${\it car}$$\rightarrow$${\it car}$)
\\[0ex]$\times$ ${\it times}$:(${\it car}$$\rightarrow$${\it car}$$\rightarrow$${\it car}$)
\\[0ex]$\times$ (${\it one}$:${\it car}$
\\[0ex]$\times$ (${\it car}$$\rightarrow$${\it car}$$\rightarrow$(?${\it car}$))))
\-
\end{tabbing}