anchor.diff:           (Env.get_range env)
          in
            
  -       lift_wp_and_bind_with env pure_assume_wp c (weaken_flags ct.flags)
  +       bind_pure_wp_with env pure_assume_wp c (weaken_flags ct.flags)
   
   let weaken_precondition env lc (f:guard_formula) : lcomp =
     let weaken () =
  
positive.code:     flags = []
    }) in
  
    let m_c, g_lift = edge.mlift.mlift_wp env pure_c in
    let bind_c, g_bind = mk_bind env pure_c None c flags r in
    bind_c, Env.conj_guard g_lift g_bind
  
  let weaken_flags flags =
      if flags |> BU.for_some (function SHOULD_NOT_INLINE -> true | _ -> false)
  
negative.code:            r
           in
  
           bind_pure_wp_with env pure_assert_wp c flags
  
  let strengthen_precondition
              (reason:option<(unit -> string)>)
  