The missing rule.
--- a/Quot/QuotMain.thy Thu Jan 21 07:38:34 2010 +0100
+++ b/Quot/QuotMain.thy Thu Jan 21 09:02:04 2010 +0100
@@ -138,6 +138,7 @@
lemma
shows QT_all: "Quot_True (All P) \<Longrightarrow> Quot_True P"
and QT_ex: "Quot_True (Ex P) \<Longrightarrow> Quot_True P"
+ and QT_ex1: "Quot_True (Ex1 P) \<Longrightarrow> Quot_True P"
and QT_lam: "Quot_True (\<lambda>x. P x) \<Longrightarrow> (\<And>x. Quot_True (P x))"
and QT_ext: "(\<And>x. Quot_True (a x) \<Longrightarrow> f x = g x) \<Longrightarrow> (Quot_True a \<Longrightarrow> f = g)"
by (simp_all add: Quot_True_def ext)