\GUARDED(\mathtt{default}~P_1~P_2) & = & \GUARDED(P_1) \wedge \GUARDED(P_2) \\
\GUARDED(\mathtt{if}~P_1~\mathtt{then}~P_2~\mathtt{else}~P_3) & = & \GUARDED(P_2) \wedge \GUARDED(P_3) \\
\GUARDED(\mathtt{fail}) & = & \TRUE \\
- \GUARDED(\mathtt{fold}~d~P_1~\mathtt{rec}~x~P_2) & = & \GUARDED(P_2)
+ \GUARDED(\mathtt{fold}~d~P_1~\mathtt{rec}~x~P_2) & = & \GUARDED(P_1)
\end{array}
\]
\hrule