Merge from LFSC (#26)

* Showing models as coq counter examples in tactic without constructing coq terms

* also read models when calling cvc4 with a file (deactivated because cvc4 crashes)

* Show counter examples with variables in the order they are quantified in the Coq goal

* Circumvent issue with ocamldep

* fix issue with dependencies

* fix issue with dependencies

* Translation and OCaml support for extract, zero_extend, sign_extend

* Show run times of components

* print time on stdout instead

* Tests now work with new version (master) of CVC4

* fix small printing issue

* look for date on mac os x

* proof of valid_check_bbShl: some cases to prove.

* full proof of "left shift checker".

*  full proof of "rigth shift checker".

* Support translation of terms bvlshr, bvshl but LFSC rules do not exists at the moment
Bug fix for bitvector extract (inverted arguments)

* Typo

* More modularity on the format of traces depending on the version of coq

* More straightforward definitions in Int63Native_standard

* Use the Int31 library with coq-8.5

* Use the most efficient operations of Int31

* Improved performance with coq-8.5

* Uniform treatment of sat and smt tactics

* Hopefully solved the problem with universes for the tactic

* Updated the installation instructions

* Holes for unsupported bit blasting rules

* Cherry-picking from smtcoq/smtcoq

* bug fix hole for bitblast

* Predefined arrays are not required anymore

* fix issue with coq bbT and bitof construction from ocaml

* bug fix in smtAtom for uninterpreted functions
fix verit test file

* fix issue with smtlib2 extract parsing

* It looks like we still need the PArray function instances for some examples (see vmcai_bytes.smt2)

* Solver specific reification:
Each solver has a list of supported theories which is passed to Atom.of_coq, this function creates uninterpreted functions / sorts for unsupported features.

* show counter-examples with const_farray instead of const for constant array definitions

* Vernacular commands to debug checkers.
Verit/Lfsc_Checker_Debug will always fail, reporting the first proof step of the certificate that failed be checked

* Update INSTALL.md

* show smtcoq proof when converting

* (Hopefully) repared the universes problems

* Corrected a bug with holes in proofs

* scripts for tests:
create a folder "work" under "lfsc/tests/", locate the benchmarks there.
create a folder "results" under "lfsc/tests/work/" in which you'll find the results of ./cvc4tocoq.

* make sure to give correct path for your benchs...

* Checker for array extensionality modulo symmetry of equality

* fix oversight with bitvectors larger than 63 bits

* some printing functions for smt2 ast

* handle smtlib2 files with more complicated equivalence with (= ... )

* revert: ./cvc4tocoq does not output lfsc proofs...

* bug fix one input was ignored

* Don't show verit translation of LFSC proof if environment variable DONTSHOWVERIT is set
(e.g. put export DONTSHOWVERIT="" in your .bashrc or .bashprofile)

* Also sort names of introduced variables when showing counter-example

* input files for which SMTCoq retuns false.

* input files for which SMTCoq retuns false.

* use debug checker for debug file

* More efficient debug checker

* better approximate number of failing step of certificate in debug checker

* fix mistake in ml4

* very first attempt to support goals in Prop

* bvs: comparison predicates in Prop and their <-> proofs with the ones in bool
farrays: equality predicate in Prop and its <-> proof with the one in bool.

* unit, Bool, Z, Pos: comparison and equality predicates in Prop.

* a typo fixed.

* an example of array equality in  Prop (converted into Bool by hand)...
TODO: enhance the search space of cvc4 tactic.

* first version of cvc4' tactic: "solves" the goals in Prop.
WARNING: supports only bv and array goals and might not be complete
TODO: add support for lia goals

* cvc4' support for lia
WARNING: might not be complete!

* small fix in cvc4' and some variations of examples

* small fix + support for goals in Bool and Bool = true + use of solve tactical
WARNING: does not support UF and INT63 goals in Prop

* cvc4': better arrangement

* cvc4': Prop2Bool by context search...

* cvc4': solve tactial added -> do not modify unsolved goals.

* developer documentation for the smtcoq repo

* cvc4': rudimentary support for uninterpreted function goals in Prop.

* cvc4': support for goals with Leibniz equality...
WARNING: necessary use of "Grab Existential Variables." to instantiate variable types for farrays!

* cvc4': Z.lt adapted + better support from verit...

* cvc4': support for Z.le, Z.ge, Z.gt.

* Try arrays with default value (with a constructor for constant arrays), but extensionality is not provable

* cvc4': support for equality over uninterpreted types

* lfsc demo: goals in Coq's Prop.

* lfsc demo: goals in Bool.

* Fix issue with existential variables generated by prop2bool.
- prop2bool tactic exported by SMTCoq
- remove useless stuff

* update usage and installation instructions

* Update INSTALL.md

* highlighting

* the tactic: bool2prop.

* clean up

* the tactic smt: very first version.

* smt: return unsolved goals in Prop.

* Show when a certificate cannot be checked when running the tactic instead of at Qed

* Tactic improvements
- Handle negation/True/False in prop/bool conversions tactic.
- Remove alias for farray (this caused problem for matching on this type in tactics).
- Tactic `smt` that combines cvc4 and veriT.
- return subgoals in prop

* test change header

* smt: support for negated goals + some reorganization.

* conflicts resolved + some reorganization.

* a way to solve the issue with ambiguous coercions.

* reorganization.

* small change.

* another small change.

* developer documentation of the tactics.

* developer guide: some improvements.

* developer guide: some more improvements.

* developer guide: some more improvements.

* developer guide: some more improvements.

* pass correct environment for conversion + better error messages

* cleaning

* ReflectFacts added.

* re-organizing developers' guide.

* re-organizing developers' guide.

* re-organizing developers' guide.

* removing unused maps.

* headers.

* artifact readme getting started...

* first attempt

* second...

* third...

* 4th...

* 5th...

* 6th...

* 7th...

* 8th...

* 9th...

* 10th...

* 11th...

* 12th...

* 13th...

* 14th...

* 15th...

* 16th...

* 17th...

* Update artifact.md

Use links to lfsc repository like in the paper

* 18th...

* 19th...

* 20th...

* 21st...

* 22nd...

* 23rd...

* 24th...

* 25th...

* 26th...

* 27th...

* 28th...

* Update artifact.md

Small reorganization

* minor edits

* More minor edits

* revised description of tactics

* Final pass

* typo

* name changed: artifact-readme.md

* file added...

* passwd chaged...

* links...

* removal

* performance statement...

* typos...

* the link to the artifact image updated...

* suggestions by Guy...

* aux files removed...

* clean-up...

* clean-up...

* some small changes...

* small fix...

* additional information on newly created files after running cvc4tocoq script...

* some small fix...

* another small fix...

* typo...

* small fix...

* another small fix...

* fix...

* link to the artifact image...

* We do not want to force vm_cast for the Theorem commands

* no_check variants of the tactics

* TODO: a veriT test does not work anymore

* Compiles with both versions of Coq

* Test of the tactics in real conditions

* Comment on this case study

* an example for the FroCoS paper.

* Fix smt tactic that doesn't return cvc4's subgoals

* readme modifications

* readme modifications 2

* small typo in readme.

* small changes in readme.

* small changes in readme.

* typo in readme.

* Sync with https://github.com/LFSC/smtcoq

* Port to Coq 8.6

* README

* README

* INSTALL

* Missing file

* Yves' proposition for installation instructions

* Updated link to CVC4

* Compiles again with native-coq

* Compiles with both versions of Coq

* Command to bypass typechecking when generating a zchaff theorem

* Solved bug on cuts from Hole

* Counter-models for uninterpreted sorts (improves issue #13)

* OCaml version note (#15)

* update .gitignore

* needs OCaml 4.04.0

* Solving merge issues (under progress)

* Make SmtBtype compile

* Compilation of SmtForm under progress

* Make SmtForm compile

* Make SmtCertif compile

* Make SmtTrace compile

* Make SatAtom compile

* Make smtAtom compile

* Make CnfParser compile

* Make Zchaff compile

* Make VeritSyntax compile

* Make VeritParser compile

* Make lfsc/tosmtcoq compile

* Make smtlib2_genconstr compile

* smtCommand under progress

* smtCommands and verit compile again

* lfsc compiles

* ml4 compiles

* Everything compiles

* All ZChaff unit tests and most verit unit tests (but taut5 and un_menteur) go through

* Most LFSC tests ok; some fail due to the problem of verit; a few fail due to an error "Not_found" to investigate

* Authors and headings

* Compiles with native-coq

* Typo

1 files changed, 124 insertions, 25 deletions

diff --git a/README.md b/README.md
index 4e960d6..0f275b6 100644
--- a/README.md
+++ b/README.md
@@ -5,11 +5,13 @@ SAT and SMT solvers.
 
 It relies on a certified checker for such witnesses. On top of it,
 vernacular commands and tactics to interface with the SAT solver zChaff
-and the SMT solver veriT are provided. It is designed in a modular way
+and the SMT solvers veriT and CVC4 are provided. It is designed in a modular way
 allowing to extend it easily to other solvers.
 
+<!--- Extraction is probably broken
 SMTCoq also provides an extracted version of the checker, that can be
 run outside Coq.
+--->
 
 The current stable version is version 1.3.
 
@@ -33,34 +35,41 @@ easily re-usable for your own usage.
 
 #### Overview
 
-The SMTCoq module can be used in Coq files via the `Require Import
-SMTCoq.` command. For each supported solver, it provides:
+After installation, the SMTCoq module can be used in Coq files via the
+`Require Import SMTCoq.` command. For each supported solver, it
+provides:
 
-- a vernacular command to check answers:
-  `XXX_Checker "problem_file" "witness_file"` returns `true` only if
-  `witness_file` contains a zChaff proof of the unsatisfiability of the
-  problem stated in `problem_file`;
+- a vernacular command to check answers: `XXX_Checker "problem_file"
+  "witness_file"` returns `true` only if `witness_file` contains a proof
+  of the unsatisfiability of the problem stated in `problem_file`;
 
 - a vernacular command to safely import theorems:
   `XXX_Theorem theo "problem_file" "witness_file"` produces a Coq term
-  `teo` whose type is the theorem stated in `problem_file` if
+  `theo` whose type is the theorem stated in `problem_file` if
   `witness_file` is a proof of the unsatisfiability of it, and fails
   otherwise.
 
-- a safe tactic to try to solve a Coq goal using the chosen solver.
+- safe tactics to try to solve a Coq goal using the chosen solver (or a
+  combination of solvers).
 
+<!--- Extraction is probably broken
 The SMTCoq checker can also be extracted to OCaml and then used
 independently from Coq.
+--->
 
+We now give more details for each solver.
+
+<!--- Extraction is probably broken
 We now give more details for each solver, and explanations on
 extraction.
+--->
 
 
 #### zChaff
 
 Compile and install zChaff as explained in the installation
 instructions. In the following, we consider that the command `zchaff` is
-in your `PATH` variable environment.
+in your `PATH` environment variable.
 
 
 ##### Checking zChaff answers of unsatisfiability and importing theorems
@@ -72,7 +81,7 @@ To check the result given by zChaff on an unsatisfiable dimacs file
   produces a proof witness file named `resolve_trace`.
 
 - In a Coq file `file.v`, put:
-```
+```coq
 Require Import SMTCoq.
 Zchaff_Checker "file.cnf" "resolve_trace".
 ```
@@ -82,7 +91,7 @@ Zchaff_Checker "file.cnf" "resolve_trace".
 
 - You can also produce Coq theorems from zChaff proof witnesses: the
   commands
-```
+```coq
 Require Import SMTCoq.
 Zchaff_Theorem theo "file.cnf" "resolve_trace".
 ```
@@ -93,17 +102,18 @@ will produce a Coq term `theo` whose type is the theorem stated in
 ##### zChaff as a Coq decision procedure
 
 The `zchaff` tactic can be used to solve any goal of the form:
-```
+```coq
 forall l, b1 = b2
 ```
-where `l` is a list of Booleans (that can be concrete terms).
+where `l` is a quantifier-free list of variables and `b1` and `b2` are
+expressions of type `bool`.
 
 
 #### veriT
 
 Compile and install veriT as explained in the installation instructions.
 In the following, we consider that the command `veriT` is in your `PATH`
-variable environment.
+environment variable.
 
 
 ##### Checking veriT answers of unsatisfiability and importing theorems
@@ -112,13 +122,13 @@ To check the result given by veriT on an unsatisfiable SMT-LIB2 file
 `file.smt2`:
 
 - Produce a veriT proof witness:
-```
+```coq
 veriT --proof-prune --proof-merge --proof-with-sharing --cnf-definitional --disable-e --disable-ackermann --input=smtlib2 --proof=file.log file.smt2
 ```
 This command produces a proof witness file named `file.log`.
 
 - In a Coq file `file.v`, put:
-```
+```coq
 Require Import SMTCoq.
 Section File.
   Verit_Checker "file.smt2" "file.log".
@@ -128,9 +138,9 @@ End File.
 - Compile `file.v`: `coqc file.v`. If it returns `true` then veriT
   indeed proved that the problem was unsatisfiable.
 
-- You can also produce Coq theorems from zChaff proof witnesses: the
+- You can also produce Coq theorems from veriT proof witnesses: the
   commands
-```
+```coq
 Require Import SMTCoq.
 Section File.
   Verit_Theorem theo "file.smt2" "file.log".
@@ -139,16 +149,105 @@ End File.
 will produce a Coq term `theo` whose type is the theorem stated in
 `file.smt2`.
 
-The theories that are currently supported are `QF_UF`, `QF_LIA`,
-`QF_IDL` and their combinations.
+The theories that are currently supported by these commands are `QF_UF`
+(theory of equality), `QF_LIA` (linear integer arithmetic), `QF_IDL`
+(integer difference logic), and their combinations.
 
 
 ##### veriT as a Coq decision procedure
 
-The `verit` tactic can be used to solve any goal of the form:
+The `verit_bool` tactic can be used to solve any goal of the form:
+```coq
+forall l, b1 = b2
+```
+where `l` is a quantifier-free list of variables and `b1` and `b2` are
+expressions of type `bool`.
+
+In addition, the `verit` tactic applies to Coq goals of sort `Prop`: it
+first converts the goal into a term of type `bool` (thanks to the
+`reflect` predicate of `SSReflect`), and then calls the previous tactic
+`verit_bool`.
+
+The theories that are currently supported by these tactics are `QF_UF`
+(theory of equality), `QF_LIA` (linear integer arithmetic), `QF_IDL`
+(integer difference logic), and their combinations.
+
+
+#### CVC4
+
+Compile and install `CVC4` as explained in the installation
+instructions. In the following, we consider that the command `cvc4` is
+in your `PATH` environment variable.
+
+
+##### Checking CVC4 answers of unsatisfiability and importing theorems
+
+To check the result given by CVC4 on an unsatisfiable SMT-LIB2 file
+`name.smt2`:
+
+- Produce a CVC4 proof witness:
+
+```bash
+cvc4 --dump-proof --no-simplification --fewer-preprocessing-holes --no-bv-eq --no-bv-ineq --no-bv-algebraic name.smt2 > name.lfsc
 ```
+
+This set of commands produces a proof witness file named `name.lfsc`.
+
+- In a Coq file `name.v`, put:
+```coq
+Require Import SMTCoq Bool List.
+Import ListNotations BVList.BITVECTOR_LIST FArray.
+Local Open Scope list_scope.
+Local Open Scope farray_scope.
+Local Open Scope bv_scope.
+
+Section File.
+  Lfsc_Checker "name.smt2" "name.lfsc".
+End File.
+```
+
+- Compile `name.v`: `coqc name.v`. If it returns `true` then the problem
+  is indeed unsatisfiable.
+
+NB: Use `cvc4tocoq` script in `src/lfsc/tests` to automatize the above steps.
+
+- Ex: `./cvc4tocoq name.smt2` returns `true` only if the problem
+  `name.smt2` has been proved unsatisfiable by CVC4.
+
+The theories that are currently supported by these commands are `QF_UF`
+(theory of equality), `QF_LIA` (linear integer arithmetic), `QF_IDL`
+(integer difference logic), `QF_BV` (theory of fixed-size bit vectors),
+`QF_A` (theory of arrays), and their combinations.
+
+
+##### CVC4 as a Coq decision procedure
+
+The `cvc4_bool` tactic can be used to solve any goal of the form:
+```coq
 forall l, b1 = b2
 ```
-where `l` is a list of Booleans. Those Booleans can be any concrete
-terms. The theories that are currently supported are `QF_UF`, `QF_LIA`,
-`QF_IDL` and their combinations.
+
+where `l` is a quantifier-free list of variables and `b1` and `b2` are
+expressions of type `bool`.
+
+In addition, the `cvc4` tactic applies to Coq goals of sort `Prop`: it
+ first converts the goal into a term of type `bool` (thanks to the
+ `reflect` predicate of `SSReflect`), it then calls the previous tactic
+ `cvc4_bool`, and it finally converts any unsolved subgoals returned by
+ CVC4 back to `Prop`, thus offering to the user the possibility to solve
+ these (usually simpler) subgoals.
+
+The theories that are currently supported by these tactics are `QF_UF`
+(theory of equality), `QF_LIA` (linear integer arithmetic), `QF_IDL`
+(integer difference logic), `QF_BV` (theory of fixed-size bit vectors),
+`QF_A` (theory of arrays), and their combinations.
+
+
+### The smt tactic
+
+The more powerful tactic `smt` combines all the previous tactics: it
+first converts the goal to a term of type `bool` (thanks to the
+`reflect` predicate of `SSReflect`), it then calls a combination of the
+`cvc4_bool` and `verit_bool` tactics, and it finally converts any
+unsolved subgoals back to `Prop`, thus offering to the user the
+possibility to solve these (usually simpler) subgoals.