use map.Map
use array.Array
use mach.c.C
use int.Int
use mach.int.UInt64

let double_free (p1 p2:ptr uint64)
  requires { offset p1 = 0 }
  requires { offset p2 = 0 }
  alias { p1.data with p2.data }
  requires { valid p1 0 }
  requires { valid p2 0 }
=
  free p1; (* resets p2 *)
  free p2