-(* TO DO: finish this *)
-Inductive WeakCoercion : Type := weakCoercion : WeakType -> WeakType -> CoreCoercion -> WeakCoercion.
-
-(* a WeakCoerVar just wraps a CoreVar and tags it with the pair of types amongst which it coerces *)
-Inductive WeakCoerVar := weakCoerVar : CoreVar -> WeakType -> WeakType -> WeakCoerVar.
-