  We exhibit a computational type theory which combines the higher-dimensional
structure of cartesian cubical type theory with the internal parametricity
primitives of parametric type theory, drawing out the similarities and
distinctions between the two along the way. The combined theory supports both
univalence and its relational equivalent, which we call relativity. We
demonstrate the use of the theory by analyzing polymorphic types, including
functions between higher inductive types, and we show by example how relativity
can be used to characterize the relational interpretation of inductive types.
