1. 27 Feb, 2018 1 commit
  2. 13 Nov, 2017 1 commit
    • Robbert Krebbers's avatar
      Improved treatment of anonymous hypotheses in the proof mode. · bb3584e7
      Robbert Krebbers authored
      The proof mode now explicitly keeps track of anonymous hypotheses (i.e.
      hypotheses that are introduced by the introduction pattern `?`). Consider:
      
        Lemma foo {M} (P Q R : uPred M) : P -∗ (Q ∗ R) -∗ Q ∗ P.
        Proof. iIntros "? [H ?]". iFrame "H". iFrame. Qed.
      
      After the `iIntros`, the goal will be:
      
        _ : P
        "H" : Q
        _ : R
        --------------------------------------∗
        Q ∗ P
      
      Anonymous hypotheses are displayed in a special way (`_ : P`). An important
      property of the new anonymous hypotheses is that it is no longer possible to
      refer to them by name, whereas before, anonymous hypotheses were given some
      arbitrary fresh name (typically prefixed by `~`).
      
      Note tactics can still operate on these anonymous hypotheses. For example, both
      `iFrame` and `iAssumption`, as well as the symbolic execution tactics, will
      use them. The only thing that is not possible is to refer to them yourself,
      for example, in an introduction, specialization or selection pattern.
      
      Advantages of the new approach:
      
      - Proofs become more robust as one cannot accidentally refer to anonymous
        hypotheses by their fresh name.
      - Fresh name generation becomes considerably easier. Since anonymous hypotheses
        are internally represented by natural numbers (of type `N`), we can just fold
        over the hypotheses and take the max plus one. This thus solve issue #101.
      bb3584e7
  3. 14 Mar, 2017 2 commits
  4. 18 Feb, 2017 1 commit
  5. 09 Feb, 2017 1 commit
  6. 06 Feb, 2017 1 commit
  7. 24 Jan, 2017 2 commits
  8. 05 Jan, 2017 1 commit
  9. 03 Jan, 2017 1 commit
  10. 09 Dec, 2016 1 commit
  11. 24 Nov, 2016 1 commit
  12. 19 Nov, 2016 1 commit
  13. 27 Oct, 2016 1 commit
  14. 25 Oct, 2016 2 commits
    • Robbert Krebbers's avatar
      Generalize update tactics into iMod and iModIntro for modalities. · fc30ca08
      Robbert Krebbers authored
      There are now two proof mode tactics for dealing with modalities:
      
      - `iModIntro` : introduction of a modality
      - `iMod pm_trm as (x1 ... xn) "ipat"` : eliminate a modality
      
      The behavior of these tactics can be controlled by instances of the `IntroModal`
      and `ElimModal` type class. We have declared instances for later, except 0,
      basic updates and fancy updates. The tactic `iMod` is flexible enough that it
      can also eliminate an updates around a weakest pre, and so forth.
      
      The corresponding introduction patterns of these tactics are `!>` and `>`.
      
      These tactics replace the tactics `iUpdIntro`, `iUpd` and `iTimeless`.
      
      Source of backwards incompatability: the introduction pattern `!>` is used for
      introduction of arbitrary modalities. It used to introduce laters by stripping
      of a later of each hypotheses.
      fc30ca08
    • Robbert Krebbers's avatar
      Rename rvs -> bupd (basic update), pvs -> fupd (fancy update). · 1b85d654
      Robbert Krebbers authored
      And also rename the corresponding proof mode tactics.
      1b85d654
  15. 20 Sep, 2016 2 commits
  16. 09 Sep, 2016 1 commit
    • Robbert Krebbers's avatar
      Support for specialization of P₁ -★ .. -★ Pₙ -★ Q where Q is persistent. · 090aaea3
      Robbert Krebbers authored
      Before this commit, given "HP" : P and "H" : P -★ Q with Q persistent, one
      could write:
      
        iSpecialize ("H" with "#HP")
      
      to eliminate the wand in "H" while keeping the resource "HP". The lemma:
      
        own_valid : own γ x ⊢ ✓ x
      
      was the prototypical example where this pattern (using the #) was used.
      
      However, the pattern was too limited. For example, given "H" : P₁ -★ P₂ -★ Q",
      one could not write iSpecialize ("H" with "#HP₁") because P₂ -★ Q is not
      persistent, even when Q is.
      
      So, instead, this commit introduces the following tactic:
      
        iSpecialize pm_trm as #
      
      which allows one to eliminate implications and wands while being able to use
      all hypotheses to prove the premises, as well as being able to use all
      hypotheses to prove the resulting goal.
      
      In the case of iDestruct, we now check whether all branches of the introduction
      pattern start with an `#` (moving the hypothesis to the persistent context) or
      `%` (moving the hypothesis to the pure Coq context). If this is the case, we
      allow one to use all hypotheses for proving the premises, as well as for proving
      the resulting goal.
      090aaea3
  17. 05 Aug, 2016 1 commit
    • Robbert Krebbers's avatar
      More introduction patterns. · 4d8c4ac8
      Robbert Krebbers authored
      Also make those for introduction and elimination more symmetric:
      
        !%   pure introduction         %        pure elimination
        !#   always introduction       #        always elimination
        !>   later introduction        > pat    timeless later elimination
        !==> view shift introduction   ==> pat  view shift elimination
      4d8c4ac8
  18. 25 Jul, 2016 1 commit
  19. 30 Jun, 2016 1 commit
  20. 01 Jun, 2016 1 commit
  21. 24 May, 2016 2 commits
    • Robbert Krebbers's avatar
      Merge iAssert and iPvsAssert. · e965b669
      Robbert Krebbers authored
      To do so, we have introduced the specialization patterns:
      
        =>[H1 .. Hn] and =>[-H1 .. Hn]
      
      That generate a goal in which the view shift is preserved. These specialization
      patterns can also be used for e.g. iApply.
      
      Note that this machinery is not tied to primitive view shifts, and works for
      various kinds of goal (as captured by the ToAssert type class, which describes
      how to transform the asserted goal based on the main goal).
      
      TODO: change the name of these specialization patterns to reflect this
      generality.
      e965b669
    • Robbert Krebbers's avatar
      Make specialization patterns for persistent premises more uniform. · 65bfa071
      Robbert Krebbers authored
      Changes:
      - We no longer have a different syntax for specializing a term H : P -★ Q whose
        range P or domain Q is persistent. There is just one syntax, and the system
        automatically determines whether either P or Q is persistent.
      - While specializing a term, always modalities are automatically stripped. This
        gets rid of the specialization pattern !.
      - Make the syntax of specialization patterns more consistent. The syntax for
        generating a goal is [goal_spec] where goal_spec is one of the following:
      
          H1 .. Hn : generate a goal using hypotheses H1 .. Hn
         -H1 .. Hn : generate a goal using all hypotheses but H1 .. Hn
                 # : generate a goal for the premise in which all hypotheses can be
                     used. This is only allowed when specializing H : P -★ Q where
                     either P or Q is persistent.
                 % : generate a goal for a pure premise.
      65bfa071
  22. 02 May, 2016 1 commit
  23. 11 Apr, 2016 1 commit