End FREE.
Local Hint Resolve valid_block_free_1 valid_block_free_2
perm_free_1 perm_free_2 perm_free_3
valid_access_free_1 valid_access_free_inv_1: mem.
(** ** Properties related to [drop_perm] *)

Theorem range_perm_drop_1:
forall m b lo hi p m', drop_perm m b lo hi p = Some m' -> range_perm m b lo hi Cur Freeable.