Module Type ext_wf_sig.

Axiom ctx_wff_mutual :
(forall G0 a A, Typing G0 a A -> Ctx G0) /\
(forall G0 phi,   PropWff G0 phi -> Ctx G0) /\
(forall G0 D p1 p2, Iso G0 D p1 p2 -> Ctx G0) /\
(forall G0 D A B T,   DefEq G0 D A B T -> Ctx G0) /\
(forall G0, Ctx G0 -> True).