CHANGELOG.md 48.3 KB
Newer Older
Ralf Jung's avatar
Ralf Jung committed
1
In this changelog, we document "large-ish" changes to Iris that affect even the
Ralf Jung's avatar
Ralf Jung committed
2
3
4
way the logic is used on paper.  We also document changes in the Coq
development; every API-breaking change should be listed, but not every new
lemma.
5

6
7
## Iris master

Ralf Jung's avatar
Ralf Jung committed
8
9
With this release, we dropped support for Coq 8.9.

10
11
**Changes in `algebra`:**

Ralf Jung's avatar
Ralf Jung committed
12
13
* Rename `agree_op_inv'` to `to_agree_op_inv`,
  `agree_op_invL'` to `to_agree_op_inv_L`, and add
14
  `to_agree_op_invN`.
Ralf Jung's avatar
Ralf Jung committed
15
16
17
18
* Rename `auth_auth_frac_op_invL` to `auth_auth_frac_op_inv_L`,
  `excl_auth_agreeL` to `excl_auth_agree_L`,
  `frac_auth_agreeL` to `frac_auth_agree_L`, and
  `ufrac_auth_agreeL` to `ufrac_auth_agree_L`.
19
* Add constructions to define a camera through restriction of the validity predicate
Robbert Krebbers's avatar
Robbert Krebbers committed
20
  (`iso_cmra_mixin_restrict`) and through an isomorphism (`iso_cmra_mixin`).
21
22
* Add a `frac_agree` library which encapsulates `frac * agree A` for some OFE
  `A`, and provides some useful lemmas.
23
24
* Fix direction of `auth_auth_validN` to make it consistent with similar lemmas,
  e.g., `auth_auth_valid`. The direction is now `✓{n} (● a) ↔ ✓{n} a`.
25
26
27
* Rename `auth_both_valid` to `auth_both_valid_discrete` and
  `auth_both_frac_valid` to `auth_both_frac_valid_discrete`. The old name is
  used for new, stronger lemmas that do not assume discreteness.
Robbert Krebbers's avatar
Robbert Krebbers committed
28
29
30
31
32
33
34
35
* Add the view camera `view`, which generalizes the authoritative camera
  `auth` by being parameterized by a relation that relates the authoritative
  element with the fragments.
* Redefine the authoritative camera in terms of the view camera. As part of this
  change, we have removed lemmas that leaked implementation details. Hence, the
  only way to construct elements of `auth` is via the elements `●{q} a` and
  `◯ b`. The constructor `Auth`, and the projections `auth_auth_proj` and
  `auth_frag_proj` no longer exist. Lemmas that referred to these constructors
Ralf Jung's avatar
Ralf Jung committed
36
37
38
  have been removed, in particular: `auth_equivI`, `auth_validI`,
  `auth_included`, `auth_valid_discrete`, and `auth_both_op`.  For validity, use
  `auth_auth_valid*`, `auth_frag_valid*`, or `auth_both_valid*` instead.
Robbert Krebbers's avatar
Robbert Krebbers committed
39
* Rename `auth_update_core_id` into `auth_update_frac_alloc`.
Simon Friis Vindum's avatar
Simon Friis Vindum committed
40
41
* Add the camera of discardable fractions `dfrac`. This is a generalization of
  the normal fractional camera. See `theories/algebra/dfrac.v` for further information.
Robbert Krebbers's avatar
Robbert Krebbers committed
42
43
* Rename `cmra_monotone_valid` into `cmra_morphism_valid` (this rename was
  forgotten in !56).
44
45
46
47
48
* Add `gmap_view`, a camera providing a "view of a `gmap`". The authoritative
  element is any `gmap`; the fragment provides fractional ownership of a single
  key, including support for persistent read-only ownership through `dfrac`.
  See `theories/algebra/lib/gmap_view.v` for further information.
  NOTE: The API surface for `gmap_view` is experimental and subject to change.
Ralf Jung's avatar
Ralf Jung committed
49
50
51
* Move the `*_validI` and `*_equivI` lemmas to a new module, `base_logic.algebra`.
  That module is exported by `base_logic.base_logic` so it should usually be
  available everywhere without further changes.
Robbert Krebbers's avatar
Robbert Krebbers committed
52
53
* The authoritative fragment `✓ (◯ b : auth A)` is no longer definitionally
  equal to `✓ b`.
54
55
* Add `mnat_auth`, a wrapper for `auth max_nat`. The result is an authoritative
  `nat` where a fragment is a lower bound whose ownership is persistent.
56
57
* Change `*_valid` lemma statements involving fractions to use `Qp` addition and
  inequality instead of RA composition and validity.
58

Ralf Jung's avatar
Ralf Jung committed
59
60
61
62
63
**Changes in `bi`:**

* Add big op lemmas `big_op{L,L2,M,M2,S}_intuitionistically_forall` and
  `big_sepL2_forall`, `big_sepMS_forall`, `big_sepMS_impl`, and `big_sepMS_dup`.

64
65
66
67
68
69
70
71
72
**Changes in `proofmode`:**

* The proofmode now preserves user-supplied names for existentials when using
  `iDestruct ... as (?) "..."`. This is backwards-incompatible if you were
  relying on the previous automatic names (which were always "H", possibly
  freshened). It also requires some changes if you were implementing `IntoExist`
  yourself, since the typeclass now forwards names. If your instance transforms
  one `IntoExist` into another, you can generally just forward the name from the
  premise.
73
74
75
76
77
* The proofmode also preserves user-supplied names in `iIntros`, for example
  with `iIntros (?)` and `iIntros "%"`, as described for destructing
  existentials above. As part of this change, it now uses a base name of `H` for
  pure facts rather than the previous default of `a`. This also requires some
  changes if you were implementing `FromForall`, in order to forward names.
Robbert Krebbers's avatar
Robbert Krebbers committed
78
79
80
81
82
* Make `iFrame` "less" smart w.r.t. clean up of modalities. It now consistently
  removes the modalities `<affine>`, `<absorbing>`, `<persistent>` and `□` only
  if the result after framing is `True` or `emp`. In particular, it no longer
  removes `<affine>` if the result after framing is affine, and it no longer
  removes `□` if the result after framing is intuitionistic.
Robbert Krebbers's avatar
Robbert Krebbers committed
83
84
85
* Allow framing below an `<affine>` modality if the hypothesis that is framed is
  affine. (Previously, framing below `<affine>` was only possible if the
  hypothesis that is framed resides in the intuitionistic context.)
Robbert Krebbers's avatar
Robbert Krebbers committed
86
87
88
* Remove the laws `pure_forall_2 : (∀ a, ⌜ φ a ⌝) ⊢ ⌜ ∀ a, φ a ⌝` from the BI
  interface and factor it into a type class `BiPureForall`.
* Add notation `¬ P` for `P → False` to `bi_scope`.
89

90
91
92
93
**Changes in `base_logic`:**

* Add a `ghost_var` library that provides (fractional) ownership of a ghost
  variable of arbitrary `Type`.
Ralf Jung's avatar
Ralf Jung committed
94
95
96
97
98
99
100
101
* Change type of some ghost state lemmas (mostly about allocation) to use `∗`
  instead of `∧` (consistent with our usual style).  This affects the following
  lemmas: `own_alloc_strong_dep`, `own_alloc_cofinite_dep`, `own_alloc_strong`,
  `own_alloc_cofinite`, `own_updateP`, `saved_anything_alloc_strong`,
  `saved_anything_alloc_cofinite`, `saved_prop_alloc_strong`,
  `saved_prop_alloc_cofinite`, `saved_pred_alloc_strong`,
  `saved_pred_alloc_cofinite`, `auth_alloc_strong`, `auth_alloc_cofinite`,
  `auth_alloc`.
Ralf Jung's avatar
Ralf Jung committed
102
* Change `uPred_mono` to only require inclusion at the smaller step-index.
Robbert Krebbers's avatar
Robbert Krebbers committed
103
104
105
106
107
108
* Put `iProp`/`iPreProp`-isomorphism into the `own` construction. This affects
  clients that define higher-order ghost state constructions. Concretely, when
  defining an `inG`, the functor no longer needs to be applied to `iPreProp`,
  but should be applied to `iProp`. This avoids clients from having to push
  through the `iProp`/`iPreProp`-isomorphism themselves, which is now handled
  once and for all by the `own` construction.
109
110
111
112
* Rename `gen_heap_ctx` to `gen_heap_interp`, since it is meant to be used in
  the state interpretation of WP and since `_ctx` is elsewhere used as a suffix
  indicating "this is a persistent assumption that clients should always have in
  their context". Likewise, rename `proph_map_ctx` to `proph_map_interp`.
Ralf Jung's avatar
Ralf Jung committed
113
114
115
116
* Move `uPred.prod_validI`, `uPred.option_validI`, and
  `uPred.discrete_fun_validI` to the new `base_logic.algebra` module. That
  module is exported by `base_logic.base_logic` so these names are now usually
  available everywhere, and no longer inside the `uPred` module.
117
118
119
* Add an `mnat` library on top of `mnat_auth` that supports ghost state which is
  an authoritative, monotonically-increasing `nat` with a proposition giving a
  persistent lower bound. See `base_logic.lib.mnat` for further details.
Ralf Jung's avatar
Ralf Jung committed
120
121
122
123
* Remove the `gen_heap` notations `l ↦ -` and `l ↦{q} -`. They were barely used
  and looked very confusing in context: `l ↦ - ∗ P` looks like a magic wand.
* Change `gen_inv_heap` notation `l ↦□ I` to `l ↦_I □`, so that `↦□` can be used
  by `gen_heap`.
Ralf Jung's avatar
Ralf Jung committed
124
125
* Strengthen `mapsto_valid_2` conclusion from `✓ (q1 + q2)%Qp` to
  `⌜✓ (q1 + q2)%Qp ∧ v1 = v2⌝`.
126

127
128
129
130
131
132
**Changes in `program_logic`:**

* `wp_strong_adequacy` now applies to an initial state with multiple
  threads instead of only a single thread. The derived adequacy lemmas
  are unchanged.

Ralf Jung's avatar
Ralf Jung committed
133
134
135
136
137
138
The following `sed` script helps adjust your code to the renaming (on macOS,
replace `sed` by `gsed`, installed via e.g. `brew install gnu-sed`).
Note that the script is not idempotent, do not run it twice.
```
sed -i -E -f- $(find theories -name "*.v") <<EOF
# agree and L suffix renames
Ralf Jung's avatar
Ralf Jung committed
139
140
s/\bagree_op_inv'/to_agree_op_inv/g
s/\bagree_op_invL'/to_agree_op_inv_L/g
Ralf Jung's avatar
Ralf Jung committed
141
142
s/\bauth_auth_frac_op_invL\b/auth_auth_frac_op_inv_L/g
s/\b(excl|frac|ufrac)_auth_agreeL/\1_auth_agree_L/g
143
144
145
# auth_both_valid
s/\bauth_both_valid\b/auth_both_valid_discrete/g
s/\bauth_both_frac_valid\b/auth_both_frac_valid_discrete/g
146
147
148
# gen_heap_ctx and proph_map_ctx
s/\bgen_heap_ctx\b/gen_heap_interp/g
s/\bproph_map_ctx\b/proph_map_interp/g
Ralf Jung's avatar
Ralf Jung committed
149
150
151
EOF
```

Ralf Jung's avatar
Ralf Jung committed
152
## Iris 3.3.0 (released 2020-07-15)
Robbert Krebbers's avatar
Robbert Krebbers committed
153

Ralf Jung's avatar
Ralf Jung committed
154
This release does not have any outstanding highlights, but contains a large
Ralf Jung's avatar
Ralf Jung committed
155
number of improvements all over the board.  For instance:
Ralf Jung's avatar
Ralf Jung committed
156
157

* `heap_lang` now supports deallocation as well as better reasoning about
Ralf Jung's avatar
Ralf Jung committed
158
159
  "invariant locations" (locations that perpetually satisfy some Coq-level
  invariant).
Ralf Jung's avatar
Ralf Jung committed
160
161
162
163
164
* Invariants (`inv N P`) are more flexible, now also supporting splitting
  and merging of invariants with respect to separating conjunction.
* Performance of the proofmode for BIs constructed on top of other BIs (e.g.,
  `monPred`) was greatly improved, leading to up to 70% speedup in individual
  files. As part of this refactoring, the proofmode can now also be instantiated
Ralf Jung's avatar
Ralf Jung committed
165
166
167
168
169
  with entirely "logical" notion of BIs that do not have a (non-trivial) metric
  structure, and still support reasoning about ▷.
* The proof mode now provides experimental support for naming pure facts in
  intro patterns.  See
  [iris/string-ident](https://gitlab.mpi-sws.org/iris/string-ident) for details.
Ralf Jung's avatar
Ralf Jung committed
170
171
172
173
174
175
176
177
* Iris now provides official ASCII notation. We still recommend using the
  Unicode notation for better consistency and interoperability with other Iris
  libraries, but provide ASCII notation for when Unicode is not an option.
* We removed several coercions, fixing "ambiguous coercion path" warnings and
  solving some readability issues.
* Coq 8.10, 8.11, and 8.12 are newly supported by this release, and Coq 8.7 and
  8.8 are no longer supported.

Ralf Jung's avatar
Ralf Jung committed
178
179
Further details are given in the changelog below. We always first list the
potentially breaking changes, then (some of) the additions.
Ralf Jung's avatar
Ralf Jung committed
180
181
182
183
184
185

This release of Iris received contributions by Abel Nieto, Amin Timany, Dan
Frumin, Derek Dreyer, Dmitry Khalanskiy, Gregory Malecha, Jacques-Henri Jourdan,
Jonas Kastberg, Jules Jacobs, Matthieu Sozeau, Maxime Dénès, Michael Sammler,
Paolo G. Giarrusso, Ralf Jung, Robbert Krebbers, Simon Friis Vindum, Simon
Spies, and Tej Chajed.  Thanks a lot to everyone involved!
Ralf Jung's avatar
Ralf Jung committed
186

187
**Changes in `heap_lang`:**
Ralf Jung's avatar
Ralf Jung committed
188

Ralf Jung's avatar
Ralf Jung committed
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
* Remove global `Open Scope Z_scope` from `heap_lang.lang`, and leave it up to
  reverse dependencies if they want to `Open Scope Z_scope` or not.
* Fix all binary operators performing pointer arithmetic (instead of just the
  dedicated `OffsetOp` operator doing that).
* Rename `heap_lang.lifting` to `heap_lang.primitive_laws`. There now also
  exists `heap_lang.derived_laws`.
* Make lemma names for `fill` more consistent
  - Use the `_inv` suffix for the the backwards directions:
   `reducible_fill``reducible_fill_inv`,
   `reducible_no_obs_fill``reducible_no_obs_fill_inv`,
   `not_stuck_fill``not_stuck_fill_inv`.
  - Use the non-`_inv` names (that freed up) for the forwards directions:
   `reducible_fill`, `reducible_no_obs_fill`, `irreducible_fill_inv`.
* Remove namespace `N` from `is_lock`.

Ralf Jung's avatar
Ralf Jung committed
204
205
206
* Add support for deallocation of locations via the `Free` operation.
* Add a fraction to the heap_lang `array` assertion.
* Add `lib.array` module for deallocating, copying and cloning arrays.
Ralf Jung's avatar
Ralf Jung committed
207
208
209
210
* Add TWP (total weakest-pre) lemmas for arrays.
* Add a library for "invariant locations": heap locations that will not be
  deallocated (i.e., they are GC-managed) and satisfy some pure, Coq-level
  invariant.  See `iris.base_logic.lib.gen_inv_heap` for details.
Ralf Jung's avatar
Ralf Jung committed
211
* Add the ghost state for "invariant locations" to `heapG`.  This affects the
Ralf Jung's avatar
Ralf Jung committed
212
213
  statement of `heap_adequacy`, which is now responsible for initializing the
  "invariant locations" invariant.
214
* Add lemma `mapsto_mapsto_ne : ¬ ✓(q1 + q2)%Qp → l1 ↦{q1} v1 -∗ l2 ↦{q2} v2 -∗ ⌜l1 ≠ l2⌝`.
Ralf Jung's avatar
Ralf Jung committed
215
* Add lemma `is_lock_iff` and show that `is_lock` is contractive.
Ralf Jung's avatar
Ralf Jung committed
216

217
**Changes in `program_logic`:**
Ralf Jung's avatar
Ralf Jung committed
218
219
220
221
222

* In the axiomatization of ectx languages, replace the axiom of positivity of
  context composition with an axiom that says if `fill K e` takes a head step,
  then either `K` is the empty evaluation context or `e` is a value.

Ralf Jung's avatar
Ralf Jung committed
223
**Changes in the logic (`base_logic`, `bi`):**
Robbert Krebbers's avatar
Robbert Krebbers committed
224

Ralf Jung's avatar
Ralf Jung committed
225
* Rename some accessor-style lemmas to consistently use the suffix `_acc`
Ralf Jung's avatar
Ralf Jung committed
226
  instead of `_open`:
227
228
229
230
231
  `inv_open``inv_acc`, `inv_open_strong``inv_acc_strong`,
  `inv_open_timeless``inv_acc_timeless`, `na_inv_open``na_inv_acc`,
  `cinv_open``cinv_acc`, `cinv_open_strong``cinv_acc_strong`,
  `auth_open``auth_acc`, `sts_open``sts_acc`.
  To make this work, also rename `inv_acc``inv_alter`.
Ralf Jung's avatar
Ralf Jung committed
232
233
  (Most developments should be unaffected as the typical way to invoke these
  lemmas is through `iInv`, and that does not change.)
Robbert Krebbers's avatar
Robbert Krebbers committed
234
235
236
237
* Change `inv_iff`, `cinv_iff` and `na_inv_iff` to make order of arguments
  consistent and more convenient for `iApply`. They are now of the form
  `inv N P -∗ ▷ □ (P ↔ Q) -∗ inv N Q` and (similar for `na_inv_iff` and
  `cinv_iff`), following e.g., `inv_alter` and `wp_wand`.
Ralf Jung's avatar
Ralf Jung committed
238
239
* Rename `inv_sep_1``inv_split_1`, `inv_sep_2``inv_split_2`, and
  `inv_sep``inv_split` to be consistent with the naming convention in boxes.
Ralf Jung's avatar
Ralf Jung committed
240
241
242
243
* Update the strong variant of the accessor lemma for cancellable invariants to
  match that of regular invariants, where you can pick the mask at a later time.
  (The other part that makes it strong is that you get back the token for the
  invariant immediately, not just when the invariant is closed again.)
Ralf Jung's avatar
Ralf Jung committed
244
245
* Rename `iProp`/`iPreProp` to `iPropO`/`iPrePropO` since they are `ofeT`s.
  Introduce `iProp` for the `Type` carrier of `iPropO`.
Robbert Krebbers's avatar
Robbert Krebbers committed
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
* Flatten the BI hierarchy by merging the `bi` and `sbi` canonical structures.
  This gives significant performance benefits on developments that construct BIs
  from BIs (e.g., use `monPred`). For, example it gives a performance gain of 37%
  overall on lambdarust-weak, with improvements for individual files up to 72%,
  see Iris issue #303. The concrete changes are as follows:
  + The `sbi` canonical structure has been removed.
  + The `bi` canonical structure contains the later modality. It does not
    require the later modality to be contractive or to satisfy the Löb rule, so
    we provide a smart constructor `bi_later_mixin_id` to get the later axioms
    "for free" if later is defined to be the identity function.
  + There is a separate class `BiLöb`, and a "free" instance of that class if
    the later modality is contractive. A `BiLöb` instance is required for the
    `iLöb` tactic, and for timeless instances of implication and wand.
  + There is a separate type class `BiInternalEq` for BIs with a notion of
    internal equality (internal equality was part of `sbi`). An instance of this
    class is needed for the `iRewrite` tactic, and the various lemmas about
    internal equality.
  + The class `SbiEmbed` has been removed and been replaced by classes
    `BiEmbedLater` and `BiEmbedInternalEq`.
  + The class `BiPlainly` has been generalized to BIs without internal equality.
    As a consequence, there is a separate class `BiPropExt` for BIs with
    propositional extensionality (i.e., `■ (P ∗-∗ Q) ⊢ P ≡ Q`).
  + The class `BiEmbedPlainly` is a bi-entailment (i.e., `⎡■ P⎤ ⊣⊢ ■ ⎡P⎤`
    instead of `■ ⎡P⎤ ⊢ ⎡■ P⎤`) as it has been generalized to BIs without a
    internal equality. In the past, the left-to-right direction was obtained for
    "free" using the rules of internal equality.
Ralf Jung's avatar
Ralf Jung committed
272
273
274
275
* Remove coercion from `iProp` (and other MoSeL propositions) to `Prop`.
  Instead, use the new unary notation `⊢ P`, or `⊢@{PROP} P` if the proposition
  type cannot be inferred. This also means that `%I` should not be necessary any
  more when stating lemmas, as `P` above is automatically parsed in scope `%I`.
Ralf Jung's avatar
Ralf Jung committed
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
* Some improvements to the `bi/lib/core` construction:
  + Rename `coreP_wand` into `coreP_entails` since it does not involve wands.
  + Generalize `coreP_entails` to non-affine BIs, and prove more convenient
    version `coreP_entails'` for `coreP P` with `P` affine.
  + Add instance `coreP_affine P : Affine P → Affine (coreP P)` and
    lemma `coreP_wand P Q : <affine> ■ (P -∗ Q) -∗ coreP P -∗ coreP Q`.
* Remove notation for 3-mask step-taking updates, and made 2-mask notation less
  confusing by distinguishing it better from mask-changing updates.
  Old: `|={Eo,Ei}▷=> P`. New: `|={Eo}[Ei]▷=> P`.
  Here, `Eo` is the "outer mask" (used at the beginning and end) and `Ei` the
  "inner mask" (used around the ▷ in the middle).
  As part of this, the lemmas about the 3-mask variant were changed to be about
  the 2-mask variant instead, and `step_fupd_mask_mono` now also has a more
  consistent argument order for its masks.

* Add a counterexample showing that sufficiently powerful cancellable invariants
  with a linear token subvert the linearity guarantee (see
  `bi.lib.counterexmples` for details).
* Redefine invariants as "semantic invariants" so that they support
  splitting and other forms of weakening.
* Add lemmas `inv_combine` and `inv_combine_dup_l` for combining invariants.
* Add the type `siProp` of "plain" step-indexed propositions, together with
  basic proofmode support.
Ralf Jung's avatar
Ralf Jung committed
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
* New ASCII versions of Iris notations. These are marked parsing only and
  can be made available using `Require Import iris.bi.ascii`. The new
  notations are (notations marked [†] are disambiguated using notation scopes):
  - entailment: `|-` for `⊢` and `-|-` for `⊣⊢`
  - logic[†]: `->` for `→`, `/\\` for `∧`, `\\/` for `∨`, and `<->` for `↔`
  - quantifiers[†]: `forall` for `∀` and `exists` for `∃`
  - separation logic: `**` for `∗`, `-*` for `-∗`, and `*-*` for `∗-∗`
  - step indexing: `|>` for `▷`
  - modalities: `<#>` for `□` and `<except_0>` for `◇`
  - most derived notations can be computed from previous notations using the
    substitutions above, e.g. replace `∗` with `*` and `▷` with `|>`. Examples
    include the following:
    - `|={E1,E2}=* P` for `|={E1,E2}=∗`
    - `P ={E}=* Q` for `P ={E}=∗ Q`
    - `P ={E1,E2}=* Q` for `P ={E1,E2}=∗ Q`
Ralf Jung's avatar
Ralf Jung committed
314
    - `|={E1}[E2]|>=> Q` for `|={E1}[E2]▷=> Q`
Ralf Jung's avatar
Ralf Jung committed
315
316
317
318
319
    The full list can be found in [theories/bi/ascii.v](theories/bi/ascii.v),
    where the ASCII notations are defined in terms of the unicode notations.
* Add affine, absorbing, persistent and timeless instances for telescopes.
* Add a construction `bi_rtc` to create reflexive transitive closures of
  PROP-level binary relations.
320
321
322
323
* Slightly strengthen the lemmas `big_sepL_nil'`, `big_sepL2_nil'`,
  `big_sepM_nil'` `big_sepM2_empty'`, `big_sepS_empty'`, and `big_sepMS_empty'`.
  They now only require that the argument `P` is affine instead of the whole BI
  being affine.
Ralf Jung's avatar
Ralf Jung committed
324
325
326
327
328
329
* Add `big_sepL_insert_acc`, a variant of `big_sepL_lookup_acc` which allows
  updating the value.
* Add many missing `Proper`/non-expansiveness lemmas for big-ops.
* Add `big_*_insert_delete` lemmas to split a `<[i:=x]> m` map into `i` and the rest.
* Seal the definitions of `big_opS`, `big_opMS`, `big_opM` and `big_sepM2`
  to prevent undesired simplification.
330
* Fix `big_sepM2_fmap*` only working for `nat` keys.
Ralf Jung's avatar
Ralf Jung committed
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352

**Changes in `proofmode`:**

* Make use of `notypeclasses refine` in the implementation of `iPoseProof` and
  `iAssumption`, see <https://gitlab.mpi-sws.org/iris/iris/merge_requests/329>.
  This has two consequences:
  1. Coq's "new" unification algorithm (the one in `refine`, not the "old" one
     in `apply`) is used more often by the proof mode tactics.
  2. Due to the use of `notypeclasses refine`, TC constraints are solved less
     eagerly, see <https://github.com/coq/coq/issues/6583>.
  In order to port your development, it is often needed to instantiate evars
  explicitly (since TC search is performed less eagerly), and in few cases it is
  needed to unfold definitions explicitly (due to new unification algorithm
  behaving differently).
* Strengthen the tactics `iDestruct`, `iPoseProof`, and `iAssert`:
  - They succeed in certain cases where they used to fail.
  - They keep certain hypotheses in the intuitionistic context, where they were
    moved to the spatial context before.
  The latter can lead to stronger proof mode contexts, and therefore to
  backwards incompatibility. This can usually be fixed by manually clearing some
  hypotheses. A more detailed description of the changes can be found in
  <https://gitlab.mpi-sws.org/iris/iris/merge_requests/341>.
Ralf Jung's avatar
Ralf Jung committed
353
354
355
356
357
358
* Remove the long-deprecated `cofeT` alias (for `ofeT`) and `dec_agree` RA (use
  `agree` instead).

* Add `auto` hint for `∗-∗`.
* Add new tactic `iStopProof` to turn the proof mode entailment into an ordinary
  Coq goal `big star of context ⊢ proof mode goal`.
Ralf Jung's avatar
Ralf Jung committed
359
360
361
362
363
364
365
366
367
368
* Add new introduction pattern `-# pat` that moves a hypothesis from the
  intuitionistic context to the spatial context.
* The tactic `iAssumption` also recognizes assumptions `⊢ P` in the Coq context.
* Better support for telescopes in the proof mode, i.e., all tactics should
  recognize and distribute telescopes now.
* The proof mode now supports names for pure facts in intro patterns. Support
  requires implementing `string_to_ident`. Without this tactic such patterns
  will fail. We provide one implementation using Ltac2 which works with Coq 8.11
  and can be installed with opam; see
  [iris/string-ident](https://gitlab.mpi-sws.org/iris/string-ident) for details.
Ralf Jung's avatar
Ralf Jung committed
369

370
371
372
373
374
375
**Changes in `algebra`:**

* Remove `Core` type class for defining the total core; it is now always
  defined in terms of the partial core. The only user of this type class was the
  STS RA.
* The functions `{o,r,ur}Functor_diag` are no longer coercions, and renamed into
376
377
  `{o,r,ur}Functor_apply` to better match their intent. This fixes "ambiguous
  coercion path" warnings.
378
379
* Rename `{o,r,ur}Functor_{ne,id,compose,contractive}` into
  `{o,r,ur}Functor_map_{ne,id,compose,contractive}`.
Ralf Jung's avatar
Ralf Jung committed
380
381
* Move derived camera constructions (`frac_auth` and `ufrac_auth`) to the folder
  `algebra/lib`.
382
383
384
385
386
387
388
389
390
391
392
393
394
395
* Rename `mnat` to `max_nat` and "box" it by creating a separate type for it.
* Move the RAs for `nat` and `positive` and the `mnat` RA into a separate
  module. They must now be imported from `From iris.algebra Require Import
  numbers`.
* Make names of `f_op`/`f_core` rewrite lemmas more consistent by always making
  `_core`/`_op` the suffix:
  `op_singleton``singleton_op`, `core_singleton``singleton_core`,
  `discrete_fun_op_singleton``discrete_fun_singleton_op`,
  `discrete_fun_core_singleton``discrete_fun_singleton_core`,
  `list_core_singletonM``list_singleton_core`,
  `list_op_singletonM``list_singleton_op`,
  `sts_op_auth_frag``sts_auth_frag_op`,
  `sts_op_auth_frag_up``sts_auth_frag_up_op`,
  `sts_op_frag``sts_frag_op`,
396
397
398
399
400
401
402
403
404
405
406
  `list_op_length``list_length_op`,
  `list_core_singletonM``list_singletonM_core`,
  `list_op_singletonM``list_singletonM_op`.
* All list "map singleton" lemmas consistently use `singletonM` in their name:
  `list_singleton_valid``list_singletonM_valid`,
  `list_singleton_core_id``list_singletonM_core_id`,
  `list_singleton_snoc``list_singletonM_snoc`,
  `list_singleton_updateP``list_singletonM_updateP`,
  `list_singleton_updateP'``list_singletonM_updateP'`,
  `list_singleton_update``list_singletonM_update`,
  `list_alloc_singleton_local_update``list_alloc_singletonM_local_update`.
Ralf Jung's avatar
Ralf Jung committed
407
* Remove `auth_both_op` and rename `auth_both_frac_op` into `auth_both_op`.
408
409
* Add lemma `singleton_included : {[ i := x ]} ≼ ({[ i := y ]} ↔ x ≡ y ∨ x ≼ y`,
  and rename existing asymmetric lemmas (with a singleton on just the LHS):
Ralf Jung's avatar
Ralf Jung committed
410
411
412
  `singleton_includedN``singleton_includedN_l`,
  `singleton_included``singleton_included_l`,
  `singleton_included_exclusive``singleton_included_exclusive_l`.
Ralf Jung's avatar
Ralf Jung committed
413
414
415
416
417
418
419
420
421

* Add notion `ofe_iso A B` that states that OFEs `A` and `B` are
  isomorphic. This is used in the COFE solver.
* Add `{o,r,ur}Functor_oFunctor_compose` for composition of functors.
* Add `pair_op_1` and `pair_op_2` to split a pair where one component is the unit.
* Add derived camera construction `excl_auth A` for `auth (option (excl A))`.
* Make lemma `Excl_included` a bi-implication.
* Make `auth_update_core_id` work with any fraction of the authoritative
  element.
Yusuke Matsushita's avatar
Yusuke Matsushita committed
422
* Add `min_nat`, an RA for natural numbers with `min` as the operation.
Ralf Jung's avatar
Ralf Jung committed
423
* Add many missing `Proper`/non-expansiveness lemmas for maps and lists.
Ralf Jung's avatar
Ralf Jung committed
424
425
426
427
* Add `list_singletonM_included` and `list_lookup_singletonM_{lt,gt}` lemmas
  about singletons in the list RA.
* Add `list_core_id'`, a stronger version of `list_core_id` which only talks
  about elements that are actually in the list.
428

429
430
431
The following `sed` script helps adjust your code to the renaming (on macOS,
replace `sed` by `gsed`, installed via e.g. `brew install gnu-sed`).
Note that the script is not idempotent, do not run it twice.
432
433
```
sed -i -E '
434
435
436
437
438
439
# functor renames
s/\b(o|r|ur)Functor_(ne|id|compose|contractive)\b/\1Functor_map_\2/g
# singleton_included renames
s/\bsingleton_includedN\b/singleton_includedN_l/g
s/\bsingleton_included\b/singleton_included_l/g
s/\bsingleton_included_exclusive\b/singleton_included_exclusive_l/g
440
441
442
443
# f_op/f_core renames
s/\b(op|core)_singleton\b/singleton_\1/g
s/\bdiscrete_fun_(op|core)_singleton\b/discrete_fun_singleton_\1/g
s/\bsts_op_(auth_frag|auth_frag_up|frag)\b/sts_\1_op/g
444
s/\blist_(op|core)_singletonM\b/list_singletonM_\1/g
445
s/\blist_op_length\b/list_length_op/g
446
447
448
449
450
451
452
# list "singleton map" renames
s/\blist_singleton_valid\b/list_singletonM_valid/g
s/\blist_singleton_core_id\b/list_singletonM_core_id/g
s/\blist_singleton_snoc\b/list_singletonM_snoc/g
s/\blist_singleton_updateP\b/list_singletonM_updateP/g
s/\blist_singleton_update\b/list_singletonM_update/g
s/\blist_alloc_singleton_local_update\b/list_alloc_singletonM_local_update/g
453
454
455
456
457
458
459
# inv renames
s/\binv_sep(|_1|_2)\b/inv_split\1/g
s/\binv_acc\b/inv_alter/g
s/\binv_open(|_strong|_timeless)\b/inv_acc\1/g
s/\bcinv_open(|_strong)\b/cinv_acc\1/g
s/\b(na_inv|auth|sts)_open\b/\1_acc/g
# miscellaneous
460
s/\bauth_both_frac_op\b/auth_both_op/g
461
s/\bmnat\b/max_nat/g
462
s/\bcoreP_wand\b/coreP_entails/g
463
464
465
' $(find theories -name "*.v")
```

Ralf Jung's avatar
Ralf Jung committed
466
## Iris 3.2.0 (released 2019-08-29)
Ralf Jung's avatar
Ralf Jung committed
467

Ralf Jung's avatar
Ralf Jung committed
468
469
470
The highlight of this release is the completely re-engineered interactive proof
mode.  Not only did many tactics become more powerful; the entire proof mode can
now be used not just for Iris but also for other separation logics satisfying
Ralf Jung's avatar
Ralf Jung committed
471
472
473
474
475
476
the proof mode interface (e.g., [Iron] and [GPFSL]). Also see the
[accompanying paper][MoSeL].

[Iron]: https://iris-project.org/iron/
[GPFSL]: https://gitlab.mpi-sws.org/iris/gpfsl/
[MoSeL]: https://iris-project.org/mosel/
Ralf Jung's avatar
Ralf Jung committed
477
478
479
480
481
482
483
484
485
486
487
488
489
490

Beyond that, the Iris program logic gained the ability to reason about
potentially stuck programs, and a significantly strengthened adequacy theorem
that unifies the three previously separately presented theorems.  There are now
also Hoare triples for total program correctness (but with very limited support
for invariants) and logical atomicity.

And finally, our example language HeapLang was made more realistic
(Compare-and-set got replaced by compare-exchange and limited to only compare
values that can actually be compared atomically) and more powerful, with added
support for arrays and prophecy variables.

Further details are given in the changelog below.

Ralf Jung's avatar
Ralf Jung committed
491
492
493
494
495
496
497
498
This release of Iris received contributions by Aleš Bizjak, Amin Timany, Dan
Frumin, Glen Mével, Hai Dang, Hugo Herbelin, Jacques-Henri Jourdan, Jan Menz,
Jan-Oliver Kaiser, Jonas Kastberg Hinrichsen, Joseph Tassarotti, Mackie Loeffel,
Marianna Rapoport, Maxime Dénès, Michael Sammler, Paolo G. Giarrusso,
Pierre-Marie Pédrot, Ralf Jung, Robbert Krebbers, Rodolphe Lepigre, and Tej
Chajed. Thanks a lot to everyone involved!

**Changes in the theory of Iris itself:**
Ralf Jung's avatar
Ralf Jung committed
499

500
* Change in the definition of WP, so that there is a fancy update between
Jacques-Henri Jourdan's avatar
Jacques-Henri Jourdan committed
501
502
  the quantification over the next states and the later modality. This makes it
  possible to prove more powerful lifting lemmas: The new versions feature an
Ralf Jung's avatar
Ralf Jung committed
503
  "update that takes a step".
504
505
506
* Add weakest preconditions for total program correctness.
* "(Potentially) stuck" weakest preconditions and the "plainly modality" are no
  longer considered experimental.
Ralf Jung's avatar
Ralf Jung committed
507
* Add the notion of an "observation" to the language interface, so that
Ralf Jung's avatar
Ralf Jung committed
508
509
  every reduction step can optionally be marked with an event, and an execution
  trace has a matching list of events.  Change WP so that it is told the entire
510
  future trace of observations from the beginning.
Ralf Jung's avatar
Ralf Jung committed
511
* The Löb rule is now a derived rule; it follows from later-intro, later
Ralf Jung's avatar
Ralf Jung committed
512
513
  being contractive and the fact that we can take fixpoints of contractive
  functions.
Ralf Jung's avatar
Ralf Jung committed
514
* Add atomic updates and logically atomic triples, including tactic support.
Ralf Jung's avatar
Ralf Jung committed
515
  See `heap_lang/lib/increment.v` for an example.
516
517
518
* Extend the state interpretation with a natural number that keeps track of
  the number of forked-off threads, and have a global fixed proposition that
  describes the postcondition of each forked-off thread (instead of it being
Robbert Krebbers's avatar
Robbert Krebbers committed
519
  `True`).
520
521
522
* A stronger adequacy statement for weakest preconditions that involves
  the final state, the post-condition of forked-off threads, and also applies if
  the main-thread has not terminated.
523
524
525
* The user-chosen functor used to instantiate the Iris logic now goes from
  COFEs to Cameras (it was OFEs to Cameras).

Ralf Jung's avatar
Ralf Jung committed
526
**Changes in heap_lang:**
527

528
529
530
531
532
533
534
535
* CAS (compare-and-set) got replaced by CmpXchg (compare-exchange).  The
  difference is that CmpXchg returns a pair consisting of the old value and a
  boolean indicating whether the comparison was successful and hence the
  exchange happened.  CAS can be obtained by simply projecting to the second
  component, but also providing the old value more closely models the primitive
  typically provided in systems languages (C, C++, Rust).
  The comparison by this operation also got weakened to be efficiently
  implementable: CmpXchg may only be used to compare "unboxed" values that can
Ralf Jung's avatar
Ralf Jung committed
536
537
538
539
540
  be represented in a single machine word. It is sufficient if one of the two
  compared values is unboxed.
* For consistency, the restrictions CmpXchg imposes on comparison also apply to
  the `=` binary operator. This also fixes the long-standing problem that that
  operator allowed compared closures with each other.
Ralf Jung's avatar
Ralf Jung committed
541
542
* Implement prophecy variables using the new support for "observations". The
  erasure theorem (showing that prophecy variables do not alter program
Ralf Jung's avatar
Ralf Jung committed
543
  behavior) can be found [in the iris/examples repository][prophecy-erasure].
Ralf Jung's avatar
Ralf Jung committed
544
* heap_lang now uses right-to-left evaluation order. This makes it
Ralf Jung's avatar
Ralf Jung committed
545
  significantly easier to write specifications of curried functions.
Ralf Jung's avatar
Ralf Jung committed
546
* heap_lang values are now injected in heap_lang expressions via a specific
Jacques-Henri Jourdan's avatar
Jacques-Henri Jourdan committed
547
548
  constructor of the expr inductive type. This simplifies much the tactical
  infrastructure around the language. In particular, this allow us to get rid
Robbert Krebbers's avatar
Robbert Krebbers committed
549
  the reflection mechanism that was needed for proving closedness, atomicity and
Jacques-Henri Jourdan's avatar
Jacques-Henri Jourdan committed
550
551
  "valueness" of a term. The price to pay is the addition of new
  "administrative" reductions in the operational semantics of the language.
552
553
* heap_lang now has support for allocating, accessing and reasoning about arrays
  (continuously allocated regions of memory).
Robbert Krebbers's avatar
Robbert Krebbers committed
554
* One can now assign "meta" data to heap_lang locations.
Ralf Jung's avatar
Ralf Jung committed
555

Ralf Jung's avatar
Ralf Jung committed
556
557
[prophecy-erasure]: https://gitlab.mpi-sws.org/iris/examples/blob/3f33781fe6e19cfdb25259c8194d34403f1134d5/theories/logatom/proph_erasure.v

Ralf Jung's avatar
Ralf Jung committed
558
**Changes in Coq:**
559

Ralf Jung's avatar
Ralf Jung committed
560
* An all-new generalized proof mode that abstracts away from Iris!  Major new
Ralf Jung's avatar
Ralf Jung committed
561
562
563
564
565
566
  features:
  - The proof mode can now be used with logics derived from Iris (like iGPS),
    with non-step-indexed logics and even with non-affine (i.e., linear) logics.
  - `iModIntro` is more flexible and more powerful, it now also subsumes
    `iNext` and `iAlways`.
  - General infrastructure for deriving a logic for monotone predicates over
Ralf Jung's avatar
Ralf Jung committed
567
    an existing logic (see the paper for more details).
Ralf Jung's avatar
Ralf Jung committed
568
    Developments instantiating the proof mode typeclasses may need significant
Robbert Krebbers's avatar
Robbert Krebbers committed
569
570
    changes.  For developments just using the proof mode tactics, porting should
    not be too much effort.  Notable things to port are:
Ralf Jung's avatar
Ralf Jung committed
571
572
573
574
575
  - All the BI laws moved from the `uPred` module to the `bi` module.  For
    example, `uPred.later_equivI` became `bi.later_equivI`.
  - Big-ops are automatically imported, imports of `iris.base_logic.big_op` have
    to be removed.
  - The ⊢ notation can sometimes infer different (but convertible) terms when
Robbert Krebbers's avatar
Robbert Krebbers committed
576
    searching for the BI to use, which (due to Coq limitations) can lead to
Ralf Jung's avatar
Ralf Jung committed
577
578
579
580
    failing rewrites, in particular when rewriting at function types.
* The `iInv` tactic can now be used without the second argument (the name for
  the closing update).  It will then instead add the obligation to close the
  invariant to the goal.
Ralf Jung's avatar
Ralf Jung committed
581
582
* The new `iEval` tactic can be used to execute a simplification or rewriting
  tactic on some specific part(s) of the proofmode goal.
Ralf Jung's avatar
Ralf Jung committed
583
584
* Added support for defining derived connectives involving n-ary binders using
  telescopes.
Ralf Jung's avatar
Ralf Jung committed
585
586
587
* The proof mode now more consistently "prettifies" the goal after each tactic.
  Prettification also simplifies some BI connectives, like conditional
  modalities and telescope quantifiers.
Ralf Jung's avatar
Ralf Jung committed
588
* Improved pretty-printing of Iris connectives (in particular WP and fancy
Ralf Jung's avatar
Ralf Jung committed
589
590
591
  updates) when Coq has to line-wrap the output.  This goes hand-in-hand with an
  improved test suite that also tests pretty-printing.
* Added a `gmultiset` RA.
592
* Rename `timelessP``timeless` (projection of the `Timeless` class)
Ralf Jung's avatar
Ralf Jung committed
593
594
* The CMRA axiom `cmra_extend` is now stated in `Type`, using `sigT` instead of
  in `Prop` using `exists`. This makes it possible to define the function space
Jacques-Henri Jourdan's avatar
Jacques-Henri Jourdan committed
595
  CMRA even for an infinite domain.
Robbert Krebbers's avatar
Robbert Krebbers committed
596
597
598
599
600
* Rename proof mode type classes for laters:
  - `IntoLaterN``MaybeIntoLaterN` (this one _may_ strip a later)
  - `IntoLaterN'``IntoLaterN` (this one _should_ strip a later)
  - `IntoLaterNEnv``MaybeIntoLaterNEnv`
  - `IntoLaterNEnvs``MaybeIntoLaterNEnvs`
601
602
* Rename:
  - `frag_auth_op``frac_auth_frag_op`
603
604
605
  - `cmra_opM_assoc``cmra_op_opM_assoc`
  - `cmra_opM_assoc_L``cmra_op_opM_assoc_L`
  - `cmra_opM_assoc'``cmra_opM_opM_assoc`
Robbert Krebbers's avatar
Robbert Krebbers committed
606
* `namespaces` has been moved to std++.
607
608
* Changed `IntoVal` to be directly usable for rewriting `e` into `of_val v`, and
  changed `AsVal` to be usable for rewriting via the `[v <-]` destruct pattern.
Ralf Jung's avatar
Ralf Jung committed
609
* `wp_fork` is now written in curried form.
610
* `PureExec`/`wp_pure` now supports taking multiple steps at once.
Jacques-Henri Jourdan's avatar
Jacques-Henri Jourdan committed
611
612
613
* A new tactic, `wp_pures`, executes as many pure steps as possible, excluding
  steps that would require unlocking subterms. Every impure wp_ tactic executes
  this tactic before doing anything else.
Dan Frumin's avatar
Dan Frumin committed
614
* Add `big_sepM_insert_acc`.
615
616
617
618
* Add big separating conjunctions that operate on pairs of lists (`big_sepL2`)
  and on pairs of maps (`big_sepM2`). In the former case the lists are required
  to have the same length, and in the latter case the maps are required to
  have the same domains.
Dan Frumin's avatar
Dan Frumin committed
619
620
621
* The `_strong` lemmas (e.g. `own_alloc_strong`) work for all infinite
  sets, instead of just for cofinite sets. The versions with cofinite
  sets have been renamed to use the `_cofinite` suffix.
Robbert Krebbers's avatar
Robbert Krebbers committed
622
623
624
* Remove locked value lambdas. The value scope notations `rec: f x := e` and
  `(λ: x, e)` no longer add a `locked`. Instead, we made the `wp_` tactics
  smarter to no longer unfold lambdas/recs that occur behind definitions.
Ralf Jung's avatar
Ralf Jung committed
625
* Export the fact that `iPreProp` is a COFE.
626
627
628
629
630
631
632
* The CMRA `auth` now can have fractional authoritative parts. So now `auth` has
  3 types of elements: the fractional authoritative `●{q} a`, the full
  authoritative `● a ≡ ●{1} a`, and the non-authoritative `◯ a`. Updates are
  only possible with the full authoritative element `● a`, while fractional
  authoritative elements have agreement: `✓ (●{p} a ⋅ ●{q} b) ⇒ a ≡ b`. As a
  consequence, `auth` is no longer a COFE and does not preserve Leibniz
  equality.
633
634
* Add a COFE construction (and functor) on dependent pairs `sigTO`, dual to
  `discrete_funO`.
Hai Dang's avatar
Hai Dang committed
635
636
637
638
639
640
* Rename in `auth`:
  - Use `auth_auth_proj`/`auth_frag_proj` for the projections of `auth`:
    `authoritative``auth_auth_proj` and `auth_own``auth_frag_proj`.
  - Use `auth_auth` and `auth_frag` for the injections into authoritative
    elements and non-authoritative elements respectively.
  - Lemmas for the projections and injections are renamed accordingly.
Hai Dang's avatar
Hai Dang committed
641
642
643
644
645
    For examples:
    + `authoritative_validN``auth_auth_proj_validN`
    + `auth_own_validN``auth_frag_proj_validN`
    + `auth_auth_valid` was not renamed because it was already used for the
      authoritative injection.
Hai Dang's avatar
Hai Dang committed
646
647
  - `auth_both_valid``auth_both_valid_2`
  - `auth_valid_discrete_2``auth_both_valid`
Robbert Krebbers's avatar
Robbert Krebbers committed
648
649
650
* Add the camera `ufrac` for unbounded fractions (i.e. without fractions that
  can be `> 1`) and the camera `ufrac_auth` for a variant of the authoritative
  fractional camera (`frac_auth`) with unbounded fractions.
651
652
* Changed `frac_auth` notation from `●!`/`◯!` to `●F`/`◯F`. sed script:
  `s/◯!/◯F/g; s/●!/●F/g;`.
653
654
* Lemma `prop_ext` works in both directions; its default direction is the
  opposite of what it used to be.
655
* Make direction of `f_op` rewrite lemmas more consistent: Flip `pair_op`,
Paolo G. Giarrusso's avatar
Paolo G. Giarrusso committed
656
657
  `Cinl_op`, `Cinr_op`, `cmra_morphism_op`, `cmra_morphism_pcore`,
  `cmra_morphism_core`.
Robbert Krebbers's avatar
Robbert Krebbers committed
658
659
* Rename lemmas `fupd_big_sep{L,M,S,MS}` into `big_sep{L,M,S,MS}_fupd` to be
  consistent with other such big op lemmas. Also add such lemmas for `bupd`.
660
* Rename `C` suffixes into `O` since we no longer use COFEs but OFEs. Also
Ralf Jung's avatar
Ralf Jung committed
661
  rename `ofe_fun` into `discrete_fun` and the corresponding notation `-c>` into
Ralf Jung's avatar
Ralf Jung committed
662
663
  `-d>`. The renaming can be automatically done using the following script
  (on macOS, replace `sed` by `gsed`, installed via e.g. `brew install gnu-sed`):
664
```
665
sed -i '
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
s/\bCofeMor/OfeMor/g;
s/\-c>/\-d>/g;
s/\bcFunctor/oFunctor/g;
s/\bCFunctor/OFunctor/g;
s/\b\%CF/\%OF/g;
s/\bconstCF/constOF/g;
s/\bidCF/idOF/g
s/\bdiscreteC/discreteO/g;
s/\bleibnizC/leibnizO/g;
s/\bunitC/unitO/g;
s/\bprodC/prodO/g;
s/\bsumC/sumO/g;
s/\bboolC/boolO/g;
s/\bnatC/natO/g;
s/\bpositiveC/positiveO/g;
s/\bNC/NO/g;
s/\bZC/ZO/g;
s/\boptionC/optionO/g;
s/\blaterC/laterO/g;
s/\bofe\_fun/discrete\_fun/g;
s/\bdiscrete\_funC/discrete\_funO/g;
s/\bofe\_morC/ofe\_morO/g;
s/\bsigC/sigO/g;
s/\buPredC/uPredO/g;
s/\bcsumC/csumO/g;
s/\bagreeC/agreeO/g;
s/\bauthC/authO/g;
s/\bnamespace_mapC/namespace\_mapO/g;
s/\bcmra\_ofeC/cmra\_ofeO/g;
s/\bucmra\_ofeC/ucmra\_ofeO/g;
s/\bexclC/exclO/g;
s/\bgmapC/gmapO/g;
s/\blistC/listO/g;
s/\bvecC/vecO/g;
s/\bgsetC/gsetO/g;
s/\bgset\_disjC/gset\_disjO/g;
s/\bcoPsetC/coPsetO/g;
s/\bgmultisetC/gmultisetO/g;
s/\bufracC/ufracO/g
s/\bfracC/fracO/g;
s/\bvalidityC/validityO/g;
s/\bbi\_ofeC/bi\_ofeO/g;
s/\bsbi\_ofeC/sbi\_ofeO/g;
s/\bmonPredC/monPredO/g;
s/\bstateC/stateO/g;
s/\bvalC/valO/g;
s/\bexprC/exprO/g;
s/\blocC/locO/g;
s/\bdec\_agreeC/dec\_agreeO/g;
s/\bgnameC/gnameO/g;
s/\bcoPset\_disjC/coPset\_disjO/g;
717
' $(find theories -name "*.v")
718
```
Hai Dang's avatar
Hai Dang committed
719

Ralf Jung's avatar
Ralf Jung committed
720
## Iris 3.1.0 (released 2017-12-19)
721

Ralf Jung's avatar
Ralf Jung committed
722
**Changes in and extensions of the theory:**
Ralf Jung's avatar
Ralf Jung committed
723

Ralf Jung's avatar
Ralf Jung committed
724
* Define `uPred` as a quotient on monotone predicates `M -> SProp`.
Ralf Jung's avatar
Ralf Jung committed
725
726
* Get rid of some primitive laws; they can be derived:
  `True ⊢ □ True` and `□ (P ∧ Q) ⊢ □ (P ∗ Q)`
727
* Camera morphisms have to be homomorphisms, not just monotone functions.
Ralf Jung's avatar
Ralf Jung committed
728
* Add a proof that `f` has a fixed point if `f^k` is contractive.
729
730
* Constructions for least and greatest fixed points over monotone predicates
  (defined in the logic of Iris using impredicative quantification).
Ralf Jung's avatar
Ralf Jung committed
731
* Add a proof of the inverse of `wp_bind`.
Ralf Jung's avatar
Ralf Jung committed
732
* [Experimental feature] Add new modality: ■ ("plainly").
Ralf Jung's avatar
Ralf Jung committed
733
734
735
736
737
738
739
740
* [Experimental feature] Support verifying code that might get stuck by
  distinguishing "non-stuck" vs. "(potentially) stuck" weakest
  preconditions. (See [Swasey et al., OOPSLA '17] for examples.) The non-stuck
  `WP e @ E {{ Φ }}` ensures that, as `e` runs, it does not get stuck. The stuck
  `WP e @ E ?{{ Φ }}` ensures that, as usual, all invariants are preserved while
  `e` runs, but it permits execution to get stuck. The former implies the
  latter. The full judgment is `WP e @ s; E {{ Φ }}`, where non-stuck WP uses
  *stuckness bit* `s = NotStuck` while stuck WP uses `s = MaybeStuck`.
Ralf Jung's avatar
Ralf Jung committed
741

Ralf Jung's avatar
Ralf Jung committed
742
**Changes in Coq:**
Ralf Jung's avatar
Ralf Jung committed
743

744
745
* Move the `prelude` folder to its own project:
  [coq-std++](https://gitlab.mpi-sws.org/robbertkrebbers/coq-stdpp)
Ralf Jung's avatar
Ralf Jung committed
746
747
748
749
750
751
752
753
754
755
756
* Some extensions/improvements of heap_lang:
  - Improve handling of pure (non-state-dependent) reductions.
  - Add fetch-and-add (`FAA`) operation.
  - Add syntax for all Coq's binary operations on `Z`.
* Generalize `saved_prop` to let the user choose the location of the type-level
  later.  Rename the general form to `saved_anything`.  Provide `saved_prop` and
  `saved_pred` as special cases.
* Improved big operators:
  + They are no longer tied to cameras, but work on any monoid
  + The version of big operations over lists was redefined so that it enjoys
    more definitional equalities.
Ralf Jung's avatar
Ralf Jung committed
757
* Rename some things and change notation:
758
  - The unit of a camera: `empty` -> `unit`, `∅` -> `ε`
759
  - Disjointness: `⊥` -> `##`
Ralf Jung's avatar
Ralf Jung committed
760
  - A proof mode type class `IntoOp` -> `IsOp`
761
762
763
764
765
766
  - OFEs with all elements being discrete: `Discrete` -> `OfeDiscrete`
  - OFE elements whose equality is discrete: `Timeless` -> `Discrete`
  - Timeless propositions: `TimelessP` -> `Timeless`
  - Camera elements such that `core x = x`: `Persistent` -> `CoreId`
  - Persistent propositions: `PersistentP` -> `Persistent`
  - The persistent modality: `always` -> `persistently`
767
  - Adequacy for non-stuck weakestpre: `adequate_safe` -> `adequate_not_stuck`
Ralf Jung's avatar
Ralf Jung committed
768
  - Consistently SnakeCase identifiers:
769
770
771
772
773
774
775
776
777
778
    + `CMRAMixin` -> `CmraMixin`
    + `CMRAT` -> `CmraT`
    + `CMRATotal` -> `CmraTotal`
    + `CMRAMorphism` -> `CmraMorphism`
    + `CMRADiscrete` -> `CmraDiscrete`
    + `UCMRAMixin` -> `UcmraMixin`
    + `UCMRAT` -> `UcmraT`
    + `DRAMixin` -> `DraMixin`
    + `DRAT` -> `DraT`
    + `STS` -> `Sts`
Ralf Jung's avatar
Ralf Jung committed
779
780
  - Many lemmas also changed their name.  `always_*` became `persistently_*`,
    and furthermore: (the following list is not complete)
781
782
783
784
785
786
787
788
789
790
    + `impl_wand` -> `impl_wand_1` (it only involves one direction of the
      equivalent)
    + `always_impl_wand` -> `impl_wand`
    + `always_and_sep_l` -> `and_sep_l`
    + `always_and_sep_r` -> `and_sep_r`
    + `always_sep_dup` -> `sep_dup`
    + `wand_impl_always` -> `impl_wand_persistently` (additionally,
      the direction of this equivalence got swapped for consistency's sake)
    + `always_wand_impl` -> `persistently_impl_wand` (additionally, the
      direction of this equivalence got swapped for consistency's sake)
Ralf Jung's avatar
Ralf Jung committed
791
  The following `sed` snippet should get you most of the way (on macOS you will
792
  have to replace `sed` by `gsed`, installed via e.g. `brew install gnu-sed`):
Ralf Jung's avatar
Ralf Jung committed
793
```
794
sed -i 's/\bPersistentP\b/Persistent/g; s/\bTimelessP\b/Timeless/g; s/\bCMRADiscrete\b/CmraDiscrete/g; s/\bCMRAT\b/CmraT/g; s/\bCMRAMixin\b/CmraMixin/g; s/\bUCMRAT\b/UcmraT/g; s/\bUCMRAMixin\b/UcmraMixin/g; s/\bSTS\b/Sts/g' $(find -name "*.v")
Ralf Jung's avatar
Ralf Jung committed
795
```
Ralf Jung's avatar
Ralf Jung committed
796
797
* `PersistentL` and `TimelessL` (persistence and timelessness of lists of
  propositions) are replaces by `TCForall` from std++.
Ralf Jung's avatar
Ralf Jung committed
798
799
* Fix a bunch of consistency issues in the proof mode, and make it overall more
  usable.  In particular:
800
801
802
803
804
805
806
807
808
809
  - All proof mode tactics start the proof mode if necessary; `iStartProof` is
    no longer needed and should only be used for building custom proof mode
    tactics.
  - Change in the grammar of specialization patterns: `>[...]` -> `[> ...]`
  - Various new specification patterns for `done` and framing.
  - There is common machinery for symbolic execution of pure reductions. This
    is provided by the type classes `PureExec` and `IntoVal`.
  - There is a new connective `tc_opaque`, which can be used to make definitions
    opaque for type classes, and thus opaque for most tactics of the proof
    mode.
Ralf Jung's avatar
Ralf Jung committed
810
811
812
813
814
815
816
817
  - Define Many missing type class instances for distributing connectives.
  - Implement the tactics `iIntros (?)` and `iIntros "!#"` (i.e. `iAlways`)
    using type classes. This makes them more generic, e.g., `iIntros (?)` also
    works when the universal quantifier is below a modality, and `iAlways` also
    works for the plainness modality.  A breaking change, however, is that these
    tactics now no longer work when the universal quantifier or modality is
    behind a type class opaque definition.  Furthermore, this can change the
    name of anonymous identifiers introduced with the "%" pattern.
Ralf Jung's avatar
Ralf Jung committed
818
* Make `ofe_fun` dependently typed, subsuming `iprod`.  The latter got removed.
Ralf Jung's avatar
Ralf Jung committed
819
820
821
* Define the generic `fill` operation of the `ectxi_language` construct in terms
  of a left fold instead of a right fold. This gives rise to more definitional
  equalities.
Robbert Krebbers's avatar
Robbert Krebbers committed
822
823
824
825
826
* The language hierarchy (`language`, `ectx_language`, `ectxi_language`) is now
  fully formalized using canonical structures instead of using a mixture of
  type classes and canonical structures. Also, it now uses explicit mixins. The
  file `program_logic/ectxi_language` contains some documentation on how to
  setup Iris for your language.
Ralf Jung's avatar
Ralf Jung committed
827
828
* Restore the original, stronger notion of atomicity alongside the weaker
  notion. These are `Atomic a e` where the stuckness bit `s` indicates whether
829
830
  expression `e` is weakly (`a = WeaklyAtomic`) or strongly
  (`a = StronglyAtomic`) atomic.
831
832
833
834
* Various improvements to `solve_ndisj`.
* Use `Hint Mode` to prevent Coq from making arbitrary guesses in the presence
  of evars, which often led to divergence. There are a few places where type
  annotations are now needed.
835
* The rules `internal_eq_rewrite` and `internal_eq_rewrite_contractive` are now
Ralf Jung's avatar
Ralf Jung committed
836
  stated in the logic, i.e., they are `iApply`-friendly.
837

Ralf Jung's avatar
Ralf Jung committed
838
## Iris 3.0.0 (released 2017-01-11)
839

Ralf Jung's avatar
Ralf Jung committed
840
841
842
* There now is a deprecation process.  The modules `*.deprecated` contain
  deprecated notations and definitions that are provided for backwards
  compatibility and will be removed in a future version of Iris.
Ralf Jung's avatar
Ralf Jung committed
843
* View shifts are radically simplified to just internalize frame-preserving
844
  updates.  Weakestpre is defined inside the logic, and invariants and view
Ralf Jung's avatar
Ralf Jung committed
845
  shifts with masks are also coded up inside Iris.  Adequacy of weakestpre is
846
  proven in the logic. The old ownership of the entire physical state is
Ralf Jung's avatar
Ralf Jung committed
847
848
  replaced by a user-selected predicate over physical state that is maintained
  by weakestpre.
849
* Use OFEs instead of COFEs everywhere.  COFEs are only used for solving the
850
851
  recursive domain equation.  As a consequence, CMRAs no longer need a proof of
  completeness.  (The old `cofeT` is provided by `algebra.deprecated`.)
852
* Implement a new agreement construction.  Unlike the old one, this one
853
854
  preserves discreteness.  dec_agree is thus no longer needed and has been moved
  to algebra.deprecated.
855
856
857
* Renaming and moving things around: uPred and the rest of the base logic are in
  `base_logic`, while `program_logic` is for everything involving the general
  Iris notion of a language.
858
859
860
861
* Renaming in prelude.list: Rename `prefix_of` -> `prefix` and `suffix_of` ->
  `suffix` in lemma names, but keep notation ``l1 `prefix_of` l2`` and ``l1
  `suffix_of` l2``.  `` l1 `sublist` l2`` becomes ``l1 `sublist_of` l2``. Rename
  `contains` -> `submseteq` and change `` l1 `contains` l2`` to ``l1 ⊆+ l2``.
Ralf Jung's avatar
Ralf Jung committed
862
863
864
* Slightly weaker notion of atomicity: an expression is atomic if it reduces in
  one step to something that does not reduce further.
* Changed notation for embedding Coq assertions into Iris.  The new notation is
865
  ⌜φ⌝.  Also removed `=` and `⊥` from the Iris scope.  (The old notations are
Ralf Jung's avatar
Ralf Jung committed
866
  provided in `base_logic.deprecated`.)
867
* Up-closure of namespaces is now a notation (↑) instead of a coercion.
868
869
* With invariants and the physical state being handled in the logic, there is no
  longer any reason to demand the CMRA unit to be discrete.
Ralf Jung's avatar
Ralf Jung committed
870
* The language can now fork off multiple threads at once.
871
872
* Local Updates (for the authoritative monoid) are now a 4-way relation with
  syntax-directed lemmas proving them.
Ralf Jung's avatar
Ralf Jung committed
873
874
875

## Iris 2.0

Ralf Jung's avatar
Ralf Jung committed
876
877
878
879
* [heap_lang] No longer use dependent types for expressions.  Instead, values
  carry a proof of closedness.  Substitution, closedness and value-ness proofs
  are performed by computation after reflecting into a term langauge that knows
  about values and closed expressions.
880
881
* [program_logic/language] The language does not define its own "atomic"
  predicate.  Instead, atomicity is defined as reducing in one step to a value.
882
883
884
885
886
* [program_logic] Due to a lack of maintenance and usefulness, lifting lemmas
  for Hoare triples are removed.

## Iris 2.0-rc2

Ralf Jung's avatar
Ralf Jung committed
887
This version matches the final ICFP 2016 paper.
888
889

* [algebra] Make the core of an RA or CMRA a partial function.
Ralf Jung's avatar
Ralf Jung committed
890
* [program_logic/lifting] Lifting lemmas no longer round-trip through a
Ralf Jung's avatar
Ralf Jung committed
891
892
893
  user-chosen predicate to define the configurations we can reduce to; they
  directly relate to the operational semantics.  This is equivalent and
  much simpler to read.
Ralf Jung's avatar
Ralf Jung committed
894
895
896

## Iris 2.0-rc1

Ralf Jung's avatar
Ralf Jung committed
897
This is the Coq development and Iris Documentation as submitted to ICFP 2016.