1. 13 Sep, 2019 1 commit
    • Jacques-Henri Jourdan's avatar
      Reorder Requires so that we do not depend of Export bugs. · 43a1a90f
      Jacques-Henri Jourdan authored
      The general idea is to first import/export modules which are further
      than the current one, and then import/export modules which are close
      dependencies.
      
      This commit tries to use the same order of imports for every file, and
      describes the convention in ProofGuide.md. There is one exception,
      where we do not follow said convention: in program_logic/weakestpre.v,
      using that order would break printing of texan triples (??).
      43a1a90f
  2. 06 Sep, 2019 1 commit
  3. 02 May, 2019 1 commit
  4. 01 May, 2019 1 commit
  5. 21 Feb, 2019 1 commit
  6. 20 Feb, 2019 1 commit
  7. 24 Jan, 2019 1 commit
  8. 08 Dec, 2018 1 commit
  9. 01 Nov, 2018 1 commit
  10. 11 Nov, 2017 1 commit
  11. 28 Oct, 2017 1 commit
  12. 21 Sep, 2017 1 commit
  13. 17 Aug, 2017 1 commit
  14. 12 Jun, 2017 1 commit
  15. 24 Mar, 2017 2 commits
    • Robbert Krebbers's avatar
      Make big_opL type class opaque. · 02a0929d
      Robbert Krebbers authored
      This commit fixes the issues that refolding of big operators did not work nicely
      in the proof mode, e.g., given:
      
          Goal forall M (P : nat → uPred M) l,
            ([∗ list] x ∈ 10 :: l, P x) -∗ True.
          Proof. iIntros (M P l) "[H1 H2]".
      
      We got:
      
          "H1" : P 10
          "H2" : (fix
                  big_opL (M0 : ofeT) (o : M0 → M0 → M0) (H : Monoid o) (A : Type)
                          (f : nat → A → M0) (xs : list A) {struct xs} : M0 :=
                    match xs with
                    | [] => monoid_unit
                    | x :: xs0 => o (f 0 x) (big_opL M0 o H A (λ n : nat, f (S n)) xs0)
                    end) (uPredC M) uPred_sep uPred.uPred_sep_monoid nat
                   (λ _ x : nat, P x) l
          --------------------------------------∗
          True
      
      The problem here is that proof mode looked for an instance of `IntoAnd` for
      `[∗ list] x ∈ 10 :: l, P x` and then applies the instance for separating conjunction
      without folding back the fixpoint. This problem is not specific to the Iris proof
      mode, but more of a general problem of Coq's `apply`, for example:
      
          Goal forall x l, Forall (fun _ => True) (map S (x :: l)).
          Proof.
            intros x l. constructor.
      
      Gives:
      
           Forall (λ _ : nat, True)
             ((fix map (l0 : list nat) : list nat :=
                match l0 with
                | [] => []
                | a :: t => S a :: map t
                end) l)
      
      This commit fixes this issue by making the big operators type class opaque and instead
      handle them solely via corresponding type classes instances for the proof mode tactics.
      
      Furthermore, note that we already had instances for persistence and timelessness. Those
      were really needed; computation did not help to establish persistence when the list in
      question was not a ground term. In fact, the sitation was worse, to establish persistence
      of `[∗ list] x ∈ 10 :: l, P x` it could either use the persistence instance of big ops
      directly, or use the persistency instance for `∗` first. Worst case, this can lead to an
      exponential blow up because of back tracking.
      02a0929d
    • 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