(** ** Construction 1: allocating the stack frame at function entry *)

Ltac splitall := repeat (match goal with |- _ /\ _ => split end).

Lemma sound_stack_exten: forall bc stk m bound (bc1: block_classification), sound_stack bc stk m bound -> (forall b, Plt b bound -> bc1 b = bc b) -> sound_stack bc1 stk m bound.