Module red_one := ext_red_one invert.
Export red_one.
Set Bullet Behavior "Strict Subproofs".
Set Implicit Arguments.

Lemma E_Beta2 :  ∀ (G : context) (D : available_props) (a1 a2 B : tm),
Typing G a1 B → Beta a1 a2 → DefEq G D a1 a2 B.