--- a/doc/manual.tex	Thu Mar 12 12:23:23 2009 -0400
+++ b/doc/manual.tex	Thu Mar 12 12:25:05 2009 -0400
@@ -665,6 +665,10 @@
   \Gamma \vdash c_1 :: \{\kappa\}
   & \Gamma \vdash c_2 :: \{\kappa'\}
   & \Gamma, c_1 \sim c_2 \vdash e : \tau
+}
+\quad \infer{\Gamma \vdash e \; ! : \tau}{
+  \Gamma \vdash e : [c_1 \sim c_2] \Rightarrow \tau
+  & \Gamma \vdash c_1 \sim c_2
 }$$
 
 \subsection{Pattern Typing}