include "basic_1/subst1/fwd.ma".
-theorem pr0_delta1:
+lemma pr0_delta1:
\forall (u1: T).(\forall (u2: T).((pr0 u1 u2) \to (\forall (t1: T).(\forall
(t2: T).((pr0 t1 t2) \to (\forall (w: T).((subst1 O u2 t2 w) \to (pr0 (THead
(Bind Abbr) u1 t1) (THead (Bind Abbr) u2 w)))))))))
Abbr)) (\lambda (t0: T).(\lambda (H2: (subst0 O u2 t2 t0)).(pr0_delta u1 u2 H
t1 t2 H0 t0 H2))) w H1)))))))).
-theorem pr0_subst1_back:
+lemma pr0_subst1_back:
\forall (u2: T).(\forall (t1: T).(\forall (t2: T).(\forall (i: nat).((subst1
i u2 t1 t2) \to (\forall (u1: T).((pr0 u1 u2) \to (ex2 T (\lambda (t:
T).(subst1 i u1 t1 t)) (\lambda (t: T).(pr0 t t2)))))))))
T).(subst1 i u1 t1 t)) (\lambda (t: T).(pr0 t t0)) x (subst1_single i u1 t1 x
H2) H3)))) (pr0_subst0_back u2 t1 t0 i H0 u1 H1)))))) t2 H))))).
-theorem pr0_subst1_fwd:
+lemma pr0_subst1_fwd:
\forall (u2: T).(\forall (t1: T).(\forall (t2: T).(\forall (i: nat).((subst1
i u2 t1 t2) \to (\forall (u1: T).((pr0 u2 u1) \to (ex2 T (\lambda (t:
T).(subst1 i u1 t1 t)) (\lambda (t: T).(pr0 t2 t)))))))))