(** Define what it means to evaluate a CR *)
Global Instance loopVariantCR : LoopVariant CR R :=
{
evalAtIx (cr: CR) (n: nat) := evalCR cr n
}.

(* Specifications: *)
Lemma creval_lift_br_to_cr_inverses: forall (br: BR) (n: nat),
(liftBRToCR br) # n = br # n.