the column vector is pure overhead for the way the lar solver uses lp.
Some other solver modules use column vectors b and integrate with the lp_core_solver_base. The interaction model should be reviewed.
Unused solvers should be removed to make it easier to maintain this code.
this update enables new incremental linear axioms based on division terms.
It also consolidates some of the backtracking state in nla_core / emons to use stack traces instead of custom backtracking state.
- convert reduce-args to a simplifier. Currently exposed as reduce-args2 tactic until the old tactic code gets removed.
- bug fixes in model_reconstruction trail
- allow multiple defs to be added with same pool of removed formulas
- fix tracking of function symbols instead of expressions to filter replay
- add nla_divisions to track (cheap) divisibility lemmas.
-
\brief convert p == 0 into a solved form v == r, such that
v has bounds [lo, oo) iff r has bounds [lo', oo)
v has bounds (oo,hi] iff r has bounds (oo,hi']
The solved form allows the Grobner solver identify more bounds conflicts.
A bad leading term can miss bounds conflicts.
For example for x + y + z == 0 where x, y : [0, oo) and z : (oo,0]
we prefer to solve z == -x - y instead of x == -z - y
because the solution -z - y has neither an upper, nor a lower bound.
The Grobner solver is augmented with a notion of a substitution that is applied before the solver is run.
this update integrates inferences to smt.arith.solver=6 related to grobner basis computation and handling of div/mod axioms to reconcile performance with smt.arith.solver=2.
The default of smt.arth.nl.grobner_subs_fixed is changed to 1 to make comparison with solver=2 more direct.
The selection of cluster equalities for solver=6 was reconciled with how it is done for solver=2.
* remove the bound on total iterations in simplex
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* remove unncesseray checks in get_freedom_interval_for_column()
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* fix the build of test-z3
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* Revert "remove unncesseray checks in get_freedom_interval_for_column()"
This reverts commit 6770ed85e3.
* optimize get_freedom_interval_for_column() for feasible case
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* add function lar_solver::status_feasible
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* rename status_is_feasible() to is_feasible()
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* fix the linux build
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
