+
+theorem Or_ind':
+ \forall A,B:Prop.
+ \forall P: A \lor B \to Prop.
+ (\forall p:A. P (or_introl ? ? p)) \to
+ (\forall q:B. P (or_intror ? ? q)) \to
+ \forall p:A \lor B. P p.
+ intros.
+ apply
+ (match p return \lambda p.P p with
+ [(or_introl p) \Rightarrow H p
+ |(or_intror q) \Rightarrow H1 q]).
+qed.
+