Ltac UseGetSound :=
match goal with
| [ H: get _ = Some _ |- _ ] =>
let x := fresh "EQ" in (generalize (get_op_sound _ _ _ H); intros x; simpl in x; FuncInv)
end.

Theorem combine_op_sound:
forall op args op' args',
combine_op get op args = Some(op', args') ->
eval_operation ge sp op' (map valu args') m = eval_operation ge sp op (map valu args) m.