\forall (u: T).(\forall (t1: T).(\forall (x: T).(\forall (i: nat).(\forall
(h: nat).(\forall (d: nat).((subst1 i (lift h d u) (lift h (S (plus i d)) t1)
x) \to (ex2 T (\lambda (t2: T).(eq T x (lift h (S (plus i d)) t2))) (\lambda
\forall (u: T).(\forall (t1: T).(\forall (x: T).(\forall (i: nat).(\forall
(h: nat).(\forall (d: nat).((subst1 i (lift h d u) (lift h (S (plus i d)) t1)
x) \to (ex2 T (\lambda (t2: T).(eq T x (lift h (S (plus i d)) t2))) (\lambda