1. 14 Mar, 2017 1 commit
    • 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
  2. 05 Jan, 2017 1 commit
  3. 03 Jan, 2017 1 commit
  4. 09 Dec, 2016 1 commit
  5. 08 Dec, 2016 2 commits
  6. 29 Aug, 2016 1 commit
  7. 08 Aug, 2016 1 commit
  8. 20 Jul, 2016 1 commit
  9. 19 Jul, 2016 1 commit
    • Robbert Krebbers's avatar
      Solve atomic also using reification/vm_compute. · 2966b4da
      Robbert Krebbers authored
      I also reverted 7952bca4 since there is no need for atomic to be a
      boolean predicate anymore. Moreover, I introduced a hint database
      fsaV for solving side-conditions related to FSAs, in particular,
      side-conditions related to expressions being atomic.
      2966b4da
  10. 30 Mar, 2016 1 commit