An initial update to support polymorphism from SMTLIB3 and the API (so far C, Python).
The WIP SMTLIB3 format is assumed to be supporting the following declaration
```
(declare-type-var A)
```
Whenever A is used in a type signature of a function/constant or bound quantified variable, it is taken to mean that all instantiations of A are included in the signature and assertions.
For example, if the function f is declared with signature A -> A, then there is a version of f for all instances of A.
The semantics of polymorphism appears to follow previous proposals: the instances are effectively different functions.
This may clash with some other notions, such as the type signature forall 'a . 'a -> 'a would be inhabited by a unique function (the identity), while this is not enforced in this version (and hopefully never because it is more busy work).
The C API has the function 'Z3_mk_type_variable' to create a type variable and applying functions modulo polymorphic type signatures is possible.
The kind Z3_TYPE_VAR is added to sort discriminators.
This version is considered as early alpha. It passes a first rudimentary unit test involving quantified axioms, declare-fun, define-fun, and define-fun-rec.
* patching merge
* fix the format and some warnings
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* a fix in the delta calculation
* test patching
* try a new version of get_patching_deltas
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* remove dead code from lp_tst and try optimizing patching
* add comments, replace VERIFY with lp_assert
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* cleanup
---------
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
After introducing the rewriter.sort_disjunctions option (#6774), I
noticed a segfault in a Z3 run that was working fine for me before the
PR.
I traced the difference to a slight discrepancy between the first patch
I submitted and the one we ended up merging: my first version would skip
sorting the disjuncts in mk_nflat_core, but still return BR_DONE, while
the patch in master returns BR_FAILED instead.
This patch fixes that problem, and it makes slightly more sense to me to
return a BR_DONE since, if `s` is true, some disjunct (e.g. a `false`
or a repeat) might have been simplified away. However I don't fully
understand this code.
... and I can't say I understand why the segfault happens. Perhaps that
is a separate issue?
This is the file to reproduce:
https://gist.github.com/mtzguido/b7360c74d3d2e42d89f1bd9149ad26f6
Here's a stack trace of the failure, mk_nflat_or_core is not involved.
```
(gdb) where
#0 0x0000555555b98497 in smt::context::get_lit_assignment(unsigned int) const ()
#1 0x0000555555b984cb in smt::context::get_assignment(sat::literal) const ()
#2 0x0000555555b98504 in smt::context::get_assignment(unsigned int) const ()
#3 0x0000555555ca83b8 in smt::context::get_assignment_core(expr*) const ()
#4 0x0000555555c9af5a in smt::context::get_assignment(expr*) const ()
#5 0x0000555555d7bd1d in (anonymous namespace)::has_child_assigned_to(smt::context&, app*, lbool, expr*&, unsigned int) ()
#6 0x0000555555d7c413 in (anonymous namespace)::rel_case_split_queue::next_case_split_core(ptr_vector<expr>&, unsigned int&, unsigned int&, lbool&) ()
#7 0x0000555555d7c589 in (anonymous namespace)::rel_case_split_queue::next_case_split(unsigned int&, lbool&) ()
#8 0x0000555555c9c1b7 in smt::context::decide() ()
#9 0x0000555555ca39fd in smt::context::bounded_search() ()
#10 0x0000555555ca30c2 in smt::context::search() ()
#11 0x0000555555ca273d in smt::context::check(unsigned int, expr* const*, bool) ()
#12 0x0000555555cb166a in smt::kernel::check(unsigned int, expr* const*) ()
#13 0x0000555555cb9695 in (anonymous namespace)::smt_solver::check_sat_core2(unsigned int, expr* const*) ()
#14 0x00005555560dc0c6 in solver_na2as::check_sat_core(unsigned int, expr* const*) ()
#15 0x00005555560d73f3 in combined_solver::check_sat_core(unsigned int, expr* const*) ()
#16 0x00005555560d34e3 in solver::check_sat(unsigned int, expr* const*) ()
#17 0x0000555556097b26 in cmd_context::check_sat(unsigned int, expr* const*) ()
#18 0x0000555556082ff0 in smt2::parser::parse_check_sat() ()
#19 0x0000555556084dc0 in smt2::parser::parse_cmd() ()
#20 0x00005555560861b6 in smt2::parser::operator()() ()
#21 0x00005555560757e6 in parse_smt2_commands(cmd_context&, std::basic_istream<char, std::char_traits<char> >&, bool, params_ref const&, char const*) ()
#22 0x00005555555e8f68 in read_smtlib2_commands(char const*) ()
#23 0x00005555555ee6f6 in main ()
(gdb)
```
* patterns: add option for pattern decomposition (pi.decompose_patterns)
True by default, retaining current behavior.
* rewriter: add option for sorting of disjunctions (rewriter.sort_disjunctions)
True by default, retaining current behavior.
