(**************** EXT Weak ****************)
Module Type ext_weak_sig.
Include ext_wf_sig.

Axiom weaken_available_mutual:
(forall G1  a A,   Typing G1 a A -> True) /\
(forall G1  phi,   PropWff G1 phi -> True) /\
(forall G1 D p1 p2, Iso G1 D p1 p2 -> forall D', D [<=] D' -> Iso G1 D' p1 p2) /\
(forall G1 D A B T,   DefEq G1 D A B T -> forall D', D [<=] D' -> DefEq G1 D' A B T) /\
(forall G1 ,       Ctx G1 -> True).