Definition prog_c : com :=
  SKIP.Definition prog_g : com :=
  WHILE BTrue DO
    SKIP
  END.Definition equiv_classes : list (list com)
  (* REPLACE THIS LINE WITH ":= _your_definition_ ." *).

Theorem CAss_congruence : forall i a1 a1', aequiv a1 a1' -> cequiv (CAss i a1) (CAss i a1').