-- | Returns @True@ iff the expression is a 'Type' or 'Coercion'
-- expression at its top level
isTyCoArg :: Expr b -> Bool
isTyCoArg (Type {})     = True
isTyCoArg :: Expr b -> Bool
isTyCoArg (Type {})     = True
isTyCoArg (Type {})     = True