1. 24 Mar, 2017 1 commit
    • Robbert Krebbers's avatar
      Generic big operators that are no longer tied to CMRAs. · 6fbff46e
      Robbert Krebbers authored
      Instead, I have introduced a type class `Monoid` that is used by the big operators:
      
          Class Monoid {M : ofeT} (o : M → M → M) := {
            monoid_unit : M;
            monoid_ne : NonExpansive2 o;
            monoid_assoc : Assoc (≡) o;
            monoid_comm : Comm (≡) o;
            monoid_left_id : LeftId (≡) monoid_unit o;
            monoid_right_id : RightId (≡) monoid_unit o;
          }.
      
      Note that the operation is an argument because we want to have multiple monoids over
      the same type (for example, on `uPred`s we have monoids for `∗`, `∧`, and `∨`). However,
      we do bundle the unit because:
      
      - If we would not, the unit would appear explicitly in an implicit argument of the
        big operators, which confuses rewrite. By bundling the unit in the `Monoid` class
        it is hidden, and hence rewrite won't even see it.
      - The unit is unique.
      
      We could in principle have big ops over setoids instead of OFEs. However, since we do
      not have a canonical structure for bundled setoids, I did not go that way.
      6fbff46e
  2. 21 Mar, 2017 2 commits
  3. 22 Feb, 2017 2 commits
  4. 27 Jan, 2017 1 commit
  5. 11 Jan, 2017 2 commits
  6. 09 Jan, 2017 2 commits
  7. 05 Jan, 2017 1 commit
  8. 03 Jan, 2017 1 commit
  9. 09 Dec, 2016 1 commit
  10. 24 Nov, 2016 1 commit
  11. 22 Nov, 2016 1 commit
  12. 21 Nov, 2016 1 commit
  13. 17 Nov, 2016 1 commit
  14. 15 Nov, 2016 1 commit
  15. 03 Nov, 2016 1 commit
    • Robbert Krebbers's avatar
      Use symbol ∗ for separating conjunction. · cc31476d
      Robbert Krebbers authored
      The old choice for ★ was a arbitrary: the precedence of the ASCII asterisk *
      was fixed at a wrong level in Coq, so we had to pick another symbol. The ★ was
      a random choice from a unicode chart.
      
      The new symbol ∗ (as proposed by David Swasey) corresponds better to
      conventional practise and matches the symbol we use on paper.
      cc31476d
  16. 28 Oct, 2016 1 commit
  17. 27 Oct, 2016 1 commit
  18. 25 Oct, 2016 5 commits
  19. 05 Oct, 2016 1 commit
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  22. 09 Aug, 2016 1 commit
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  24. 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
  25. 27 Jul, 2016 2 commits
    • Robbert Krebbers's avatar
      Declare inG arguments of own_* implicit but not maximally inserted. · de9438cb
      Robbert Krebbers authored
      This way type class inference is not invokved when used in tactics
      like iPvs while not having to write an @.
      
      (Idea suggested by Ralf.)
      de9438cb
    • Robbert Krebbers's avatar
      Make type class inference for inG less eager. · a0348d7c
      Robbert Krebbers authored
      This way, it won't pick arbitrary (and possibly wrong!) inG instances
      when multiple ones are available. We achieve this by declaring:
      
        Hint Mode inG - - +
      
      So that type class inference only succeeds when the type of the ghost
      variable does not include any evars.
      
      This required me to make some minor changes throughout the whole
      development making some types explicit.
      a0348d7c
  26. 23 Jun, 2016 1 commit
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  30. 31 May, 2016 1 commit