1. 09 Jan, 2018 1 commit
  2. 18 Dec, 2017 1 commit
  3. 07 Dec, 2017 2 commits
  4. 05 Dec, 2017 2 commits
  5. 14 Nov, 2017 1 commit
  6. 09 Nov, 2017 3 commits
  7. 08 Nov, 2017 3 commits
  8. 07 Nov, 2017 1 commit
  9. 04 Nov, 2017 3 commits
  10. 01 Nov, 2017 2 commits
  11. 27 Sep, 2017 1 commit
  12. 25 Sep, 2017 1 commit
  13. 22 Mar, 2017 1 commit
  14. 14 Mar, 2017 2 commits
    • Robbert Krebbers's avatar
      Misc properties about languages. · 4e1bdcc7
      Robbert Krebbers authored
      4e1bdcc7
    • Robbert Krebbers's avatar
      Define `fill` in terms of a `foldl` over `fill_item`. · 6fc9c27e
      Robbert Krebbers authored
      This has some advantages:
      
      - Evaluation contexts behave like a proper "Huet's zipper", and thus:
        + We no longer need to reverse the list of evaluation context items in the
          `reshape_expr` tactic.
        + The `fill` function becomes tail-recursive.
      - It gives rise to more definitional equalities in simulation proofs using
        binary logical relations proofs.
      
        In the case of binary logical relations, we simulate an expressions in some
        ambient context, i.e. `fill K e`. Now, whenever we reshape `e` by turning it
        into `fill K' e'`, we end up with `fill K (fill K' e')`. In order to use the
        rules for the expression that is being simulated, we need to turn
        `fill K (fill K' e')` into `fill K'' e'` for some `K'`. In case of the old
        `foldr`-based approach, we had to rewrite using the lemma `fill_app` to
        achieve that. However, in case of the old `foldl`-based `fill`, we have that
        `fill K (fill K' e')` is definitionally equal to `fill (K' ++ K) e'` provided
        that `K'` consists of a bunch of `cons`es (which is always the case, since we
        obtained `K'` by reshaping `e`).
      
      Note that this change hardly affected `heap_lang`. Only the proof of
      `atomic_correct` broke. I fixed this by proving a more general lemma
      `ectxi_language_atomic` about `ectxi`-languages, which should have been there
      in the first place.
      6fc9c27e
  15. 14 Feb, 2017 1 commit
  16. 11 Jan, 2017 2 commits
  17. 05 Jan, 2017 1 commit
  18. 03 Jan, 2017 1 commit
  19. 09 Dec, 2016 1 commit
  20. 06 Dec, 2016 1 commit
  21. 17 Nov, 2016 1 commit
  22. 15 Nov, 2016 2 commits
  23. 25 Oct, 2016 1 commit
  24. 23 Aug, 2016 1 commit
  25. 08 Aug, 2016 1 commit
  26. 05 Aug, 2016 1 commit
    • Robbert Krebbers's avatar
      Iris 3.0: invariants and weakest preconditions encoded in the logic. · 1f589858
      Robbert Krebbers authored
      This commit features:
      
      - A simpler model. The recursive domain equation no longer involves a triple
        containing invariants, physical state and ghost state, but just ghost state.
        Invariants and physical state are encoded using (higher-order) ghost state.
      
      - (Primitive) view shifts are formalized in the logic and all properties about
        it are proven in the logic instead of the model. Instead, the core logic
        features only a notion of raw view shifts which internalizing performing frame
        preserving updates.
      
      - A better behaved notion of mask changing view shifts. In particular, we no
        longer have side-conditions on transitivity of view shifts, and we have a
        rule for introduction of mask changing view shifts |={E1,E2}=> P with
        E2 ⊆ E1 which allows to postpone performing a view shift.
      
      - The weakest precondition connective is formalized in the logic using Banach's
        fixpoint. All properties about the connective are proven in the logic instead
        of directly in the model.
      
      - Adequacy is proven in the logic and uses a primitive form of adequacy for
        uPred that only involves raw views shifts and laters.
      
      Some remarks:
      
      - I have removed binary view shifts. I did not see a way to describe all rules
        of the new mask changing view shifts using those.
      - There is no longer the need for the notion of "frame shifting assertions" and
        these are thus removed. The rules for Hoare triples are thus also stated in
        terms of primitive view shifts.
      
      TODO:
      
      - Maybe rename primitive view shift into something more sensible
      - Figure out a way to deal with closed proofs (see the commented out stuff in
        tests/heap_lang and tests/barrier_client).
      1f589858
  27. 28 Jul, 2016 1 commit
  28. 21 Jul, 2016 1 commit
    • Robbert Krebbers's avatar
      Some tweaks. · 037d8d62
      Robbert Krebbers authored
      In particular, remove ectx_language.atomic, because it seems unused
      expect for a smart constructor for language.atomic.
      037d8d62