+\begin{table}
+\caption{...}
+\hrule
+\[
+\begin{array}{rcll}
+\IOT{C[t_1,\dots,t_n]}{E} & = & C[\IOT{t_1}{E},\dots,\IOT{t_n}{E}] \\
+\IOT{\mathtt{term}~x}{E} & = & t & \mathcal{E}(x) = \mathtt{Term}~t \\
+\IOT{\mathtt{number}~x}{E} & = & n & \mathcal{E}(x) = \mathtt{Number}~n \\
+\IOT{\mathtt{ident}~x}{E} & = & y & \mathcal{E}(x) = \mathtt{String}~y \\
+\IOT{\mathtt{fresh}~x}{E} & = & y & \mathcal{E}(x) = \mathtt{String}~y \\
+\IOT{\mathtt{default}~P_1~P_2}{E} & = & \IOT{P_2}{E'} & \mathcal{E}(\NAMES(P_1)\setminus\NAMES(P_2)))=\{\mathtt{None}\} \\
+& & & \mathcal{E}'(x) =
+ \left\{
+ \begin{array}{@{}ll}
+ \bot & x \in \NAMES(P_1)\setminus\NAMES(P_2) \\
+ \mathcal{E}(x) & \mbox{otherwise} \\
+ \end{array}
+ \right. \\
+\IOT{\mathtt{default}~P_1~P_2}{E} & = & \IOT{P_2}{E'} & \mathcal{E}(\NAMES(P_1)\setminus\NAMES(P_2)))=\{\mathtt{Some}~v_1,\dots,\mathtt{Some}~v_n\} \\
+& & & \mathcal{E}'(x) =
+ \left\{
+ \begin{array}{@{}ll}
+ v & x \in \NAMES(P_1)\setminus\NAMES(P_2) \wedge \mathcal{E}(x) = \mathtt{Some}~v\\
+ \mathcal{E}(x) & \mbox{otherwise}
+ \end{array}
+ \right. \\
+\IOT{\mathtt{fold}~d~P_1~\mathtt{rec}~x~P_2}{E}
+& =
+& \IOT{P_2}{E'}
+& \mathcal{E}(\NAMES(P_2)\setminus\{x\}) = \{[]\} \\
+& & & \mathcal{E}'(y) =
+ \left\{
+ \begin{array}{@{}ll}
+ \bot & y \in \NAMES(P_2)\setminus\{x\} \\
+ \mathcal{E}(y) & \mbox{otherwise} \\
+ \end{array}
+ \right. \\
+\IOT{\mathtt{fold}~d~P_1~\mathtt{rec}~x~P_2}{E}
+& =
+& \IOT{P_2}{E'}
+& \mathcal{E}(\NAMES(P_2)\setminus\{x\}) = \{[v_{11},\dots,v_{1n}],\dots,[v_{m1},\dots,v_{mn}]\} \\
+& & & \mathcal{E}'(y) =
+ \left\{
+ \begin{array}{@{}ll}
+ \IOT{\mathtt{fold}~d~P_1~\mathtt{rec}~x~P_e}{E''} & y = x \\
+ v_1 & y\in\NAMES(P_2)\setminus\{x\} \wedge \mathcal{E}(y)=[v_1;\dots;v_n] \\
+ \mathcal{E}(y) & \mbox{otherwise} \\
+ \end{array}
+ \right. \\
+& & & \mathcal{E}''(y) =
+ \left\{
+ \begin{array}{@{}ll}
+ [v_2;\dots;v_n] & y\in\NAMES(P_2)\setminus\{x\} \wedge \mathcal{E}(y)=[v_1;\dots;v_n] \\
+ \mathcal{E}(y) & \mbox{otherwise} \\
+ \end{array}
+ \right. \\
+\end{array} \\
+\]
+\end{table}
+