transfer propagate monomial bounds to nla_solver

src/math/lp/lp_bound_propagator.h

@@ -120,171 +120,6 @@ public:
         m_column_types = &lp().get_column_types();
     }
    
-    bool is_linear(const svector<lpvar>& m, lpvar& zero_var, lpvar& non_fixed) {
-        zero_var = non_fixed = null_lpvar;
-        unsigned n_of_non_fixed = 0;
-        for (lpvar v : m) {
-            if (!this->column_is_fixed(v)) {
-                n_of_non_fixed++;
-                non_fixed = v;
-                continue;                
-            } 
-            const auto & b = get_lower_bound(v).x;
-            if (b.is_zero()) {
-                zero_var = v;
-                return true;
-            } 
-            
-        }
-        return n_of_non_fixed <= 1;
-    }
-
-    void add_bounds_for_zero_var(lpvar monic_var, lpvar zero_var) {
-        auto& lps = lp();
-        auto lambda = [zero_var,&lps]() {
-            return lps.get_bound_constraint_witnesses_for_column(zero_var);
-        };
-        TRACE("add_bound", lp().print_column_info(zero_var, tout) << std::endl;);      
-        add_lower_bound_monic(monic_var, mpq(0), false, lambda);
-        add_upper_bound_monic(monic_var, mpq(0), false, lambda);
-    }
-
-    void add_lower_bound_monic(lpvar j, const mpq& v, bool is_strict, std::function<u_dependency*()> explain_dep) {
-       TRACE("add_bound", lp().print_column_info(j, tout) << std::endl;);
-       j = lp().column_to_reported_index(j);
-       unsigned k;
-       if (!m_improved_lower_bounds.find(j, k)) {
-            m_improved_lower_bounds.insert(j,static_cast<unsigned>(m_ibounds.size()));
-            m_ibounds.push_back(implied_bound(v, j, true, is_strict, explain_dep));
-       }
-       else {
-            auto& found_bound = m_ibounds[k];
-            if (v > found_bound.m_bound || (v == found_bound.m_bound && !found_bound.m_strict && is_strict)) {
-                found_bound = implied_bound(v, j, true, is_strict, explain_dep);
-                TRACE("add_bound", lp().print_implied_bound(found_bound, tout););
-            }
-       }
-    }
-
-    void add_upper_bound_monic(lpvar j, const mpq& bound_val, bool is_strict, std::function <u_dependency* ()> explain_bound) {
-        j = lp().column_to_reported_index(j);
-        unsigned k;
-        if (!m_improved_upper_bounds.find(j, k)) {
-            m_improved_upper_bounds.insert(j, static_cast<unsigned>(m_ibounds.size()));
-            m_ibounds.push_back(implied_bound(bound_val, j, false, is_strict, explain_bound));
-        }
-        else {
-            auto& found_bound = m_ibounds[k];
-            if (bound_val > found_bound.m_bound || (bound_val == found_bound.m_bound && !found_bound.m_strict && is_strict)) {
-                found_bound = implied_bound(bound_val, j, false, is_strict, explain_bound);
-                TRACE("add_bound", lp().print_implied_bound(found_bound, tout););
-            }
-       }
-    }
-
-    void propagate_monic(lpvar monic_var, const svector<lpvar>& vars) {
-        lpvar non_fixed, zero_var;
-        if (!is_linear(vars, zero_var, non_fixed)) 
-            return;
-        
-        if (zero_var != null_lpvar) 
-            add_bounds_for_zero_var(monic_var, zero_var);
-        else {
-            rational k = rational(1);
-            for (auto v : vars)
-                if (v != non_fixed) {
-                    k *= lp().get_column_value(v).x;
-                    if (k.is_big()) return;
-                }
-            
-            if (non_fixed != null_lpvar) 
-                propagate_monic_with_non_fixed(monic_var, vars, non_fixed, k);
-            else   // all variables are fixed
-                propagate_monic_with_all_fixed(monic_var, vars, k);
-        }
-    }
-    
-    void propagate_monic_with_non_fixed(lpvar monic_var, const svector<lpvar>& vars, lpvar non_fixed, const rational& k) {
-        lp::impq bound_value;
-        bool is_strict;
-        auto& lps = lp();
-
-        if (lower_bound_is_available(non_fixed)) {
-            bound_value = lp().column_lower_bound(non_fixed);
-            is_strict = !bound_value.y.is_zero();
-            auto lambda = [vars, non_fixed,&lps]() {
-                u_dependency* dep = lps.get_column_lower_bound_witness(non_fixed);
-                for (auto v : vars) 
-                    if (v != non_fixed) 
-                        dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
-                return dep;
-            };
-            if (k.is_pos())
-                add_lower_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
-            else
-                add_upper_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
-       }
-
-       if (upper_bound_is_available(non_fixed)) {
-            bound_value = lp().column_upper_bound(non_fixed);
-            is_strict = !bound_value.y.is_zero();
-            auto lambda = [vars, non_fixed,&lps]() {
-                u_dependency* dep = lps.get_column_upper_bound_witness(non_fixed);
-                for (auto v : vars) 
-                    if (v != non_fixed) 
-                        dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
-                return dep;
-            };
-            if (k.is_neg())
-                add_lower_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
-            else
-                add_upper_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
-       }
-
-       if (lower_bound_is_available(monic_var)) {
-           auto lambda = [vars, monic_var, non_fixed,&lps]() {
-               u_dependency* dep = lps.get_column_lower_bound_witness(monic_var);
-               for (auto v : vars) {
-                   if (v != non_fixed) {
-                       dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
-                   }
-               }
-               return dep;
-           };
-           bound_value = lp().column_lower_bound(monic_var);
-           is_strict = !bound_value.y.is_zero();
-           if (k.is_pos())
-               add_lower_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
-           else
-               add_upper_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
-       }
-       
-       if (upper_bound_is_available(monic_var)) {
-            bound_value = lp().column_upper_bound(monic_var);
-            is_strict = !bound_value.y.is_zero();
-            auto lambda = [vars, monic_var, non_fixed,&lps]() {
-                u_dependency* dep = lps.get_column_upper_bound_witness(monic_var);
-                for (auto v : vars) {
-                    if (v != non_fixed) {
-                        dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
-                    }
-                }
-                return dep;
-            };
-            if (k.is_neg())
-                add_lower_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
-            else
-                add_upper_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
-       }
-    }
-
-    void propagate_monic_with_all_fixed(lpvar monic_var, const svector<lpvar>& vars, const rational& k) {
-        auto& lps = lp();
-        auto lambda = [vars,&lps]() { return lps.get_bound_constraint_witnesses_for_columns(vars); };
-        add_lower_bound_monic(monic_var, k, false, lambda);
-        add_upper_bound_monic(monic_var, k, false, lambda);
-    }
-
     column_type get_column_type(unsigned j) const {
         return (*m_column_types)[j];
     }

src/math/lp/nla_core.cpp

@@ -17,11 +17,12 @@ Author:
 #include "math/grobner/pdd_solver.h"
 #include "math/dd/pdd_interval.h"
 #include "math/dd/pdd_eval.h"
+#include "nla_core.h"
 namespace nla {
 
 typedef lp::lar_term term;
 
-core::core(lp::lar_solver& s, params_ref const& p, reslimit& lim) : m_evars(),
+core::core(lp::lar_solver& s, params_ref const& p, reslimit& lim, std_vector<lp::implied_bound>& implied_bounds) : m_evars(),
                                                                     lra(s),
                                                                     m_reslim(lim),
                                                                     m_params(p),
@@ -37,7 +38,8 @@ core::core(lp::lar_solver& s, params_ref const& p, reslimit& lim) : m_evars(),
                                                                     m_grobner(this),
                                                                     m_emons(m_evars),
                                                                     m_use_nra_model(false),
-                                                                    m_nra(s, m_nra_lim, *this) {
+                                                                    m_nra(s, m_nra_lim, *this),
+                                                                    m_implied_bounds(implied_bounds) {
     m_nlsat_delay = lp_settings().nlsat_delay();
     lra.m_find_monics_with_changed_bounds_func = [&](const indexed_uint_set& columns_with_changed_bounds) {
     for (const auto& m : m_emons) {
@@ -1837,5 +1839,210 @@ bool core::improve_bounds() {
     return bounds_improved;
 }
 
-} // end of nla
+bool core::is_linear(const svector<lpvar>& m, lpvar& zero_var, lpvar& non_fixed)
+{
+    zero_var = non_fixed = null_lpvar;
+    unsigned n_of_non_fixed = 0;
+    for (lpvar v : m) {
+        if (!this->var_is_fixed(v)) {
+            n_of_non_fixed++;
+            non_fixed = v;
+            continue;
+        }
+        const auto& b = get_lower_bound(v);
+        if (b.is_zero()) {
+            zero_var = v;
+            return true;
+        }
+    }
+    return n_of_non_fixed <= 1;
+}
+
+void core::add_lower_bound_monic(lpvar j, const lp::mpq& v, bool is_strict, std::function<u_dependency*()> explain_dep)
+{
+    TRACE("add_bound", lra.print_column_info(j, tout) << std::endl;);
+    j = lra.column_to_reported_index(j);
+    unsigned k;
+    if (!m_improved_lower_bounds.find(j, k)) {
+        m_improved_lower_bounds.insert(j, static_cast<unsigned>(m_implied_bounds.size()));
+        m_implied_bounds.push_back(lp::implied_bound(v, j, true, is_strict, explain_dep));
+    }
+    else {
+        auto& found_bound = m_implied_bounds[k];
+        if (v > found_bound.m_bound || (v == found_bound.m_bound && !found_bound.m_strict && is_strict)) {
+            found_bound = lp::implied_bound(v, j, true, is_strict, explain_dep);
+            TRACE("add_bound", lra.print_implied_bound(found_bound, tout););
+        }
+    }
+}
+
+void core::add_upper_bound_monic(lpvar j, const lp::mpq& bound_val, bool is_strict, std::function<u_dependency*()> explain_dep)
+{
+    j = lra.column_to_reported_index(j);
+    unsigned k;
+    if (!m_improved_upper_bounds.find(j, k)) {
+        m_improved_upper_bounds.insert(j, static_cast<unsigned>(m_implied_bounds.size()));
+        m_implied_bounds.push_back(lp::implied_bound(bound_val, j, false, is_strict, explain_dep));
+    }
+    else {
+        auto& found_bound = m_implied_bounds[k];
+        if (bound_val > found_bound.m_bound || (bound_val == found_bound.m_bound && !found_bound.m_strict && is_strict)) {
+            found_bound = lp::implied_bound(bound_val, j, false, is_strict, explain_dep);
+            TRACE("add_bound", lra.print_implied_bound(found_bound, tout););
+        }
+    }
+}
+
+bool core::upper_bound_is_available(unsigned j) const
+{
+    switch (get_column_type(j)) {
+        case lp::column_type::fixed:
+        case lp::column_type::boxed:
+        case lp::column_type::upper_bound:
+            return true;
+        default:
+            return false;
+    }
+}
+
+bool core::lower_bound_is_available(unsigned j) const
+{
+    switch (get_column_type(j)) {
+        case lp::column_type::fixed:
+        case lp::column_type::boxed:
+        case lp::column_type::lower_bound:
+            return true;
+        default:
+            return false;
+    }
+}
+
+void core::propagate_monic_with_non_fixed(lpvar monic_var, const svector<lpvar>& vars, lpvar non_fixed, const rational& k)
+{
+    lp::impq bound_value;
+    bool is_strict;
+    auto& lps = lra;
+
+    if (lower_bound_is_available(non_fixed)) {
+        bound_value = lra.column_lower_bound(non_fixed);
+        is_strict = !bound_value.y.is_zero();
+        auto lambda = [vars, non_fixed, &lps]() {
+            u_dependency* dep = lps.get_column_lower_bound_witness(non_fixed);
+            for (auto v : vars)
+                if (v != non_fixed)
+                    dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
+            return dep;
+        };
+        if (k.is_pos())
+            add_lower_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
+        else
+            add_upper_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
+    }
+
+    if (upper_bound_is_available(non_fixed)) {
+        bound_value = lra.column_upper_bound(non_fixed);
+        is_strict = !bound_value.y.is_zero();
+        auto lambda = [vars, non_fixed, &lps]() {
+            u_dependency* dep = lps.get_column_upper_bound_witness(non_fixed);
+            for (auto v : vars)
+                if (v != non_fixed)
+                    dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
+            return dep;
+        };
+        if (k.is_neg())
+            add_lower_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
+        else
+            add_upper_bound_monic(monic_var, k * bound_value.x, is_strict, lambda);
+    }
+
+    if (lower_bound_is_available(monic_var)) {
+        auto lambda = [vars, monic_var, non_fixed, &lps]() {
+            u_dependency* dep = lps.get_column_lower_bound_witness(monic_var);
+            for (auto v : vars) {
+                if (v != non_fixed) {
+                    dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
+                }
+            }
+            return dep;
+        };
+        bound_value = lra.column_lower_bound(monic_var);
+        is_strict = !bound_value.y.is_zero();
+        if (k.is_pos())
+            add_lower_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
+        else
+            add_upper_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
+    }
+
+    if (upper_bound_is_available(monic_var)) {
+        bound_value = lra.column_upper_bound(monic_var);
+        is_strict = !bound_value.y.is_zero();
+        auto lambda = [vars, monic_var, non_fixed, &lps]() {
+            u_dependency* dep = lps.get_column_upper_bound_witness(monic_var);
+            for (auto v : vars) {
+                if (v != non_fixed) {
+                    dep = lps.join_deps(dep, lps.get_bound_constraint_witnesses_for_column(v));
+                }
+            }
+            return dep;
+        };
+        if (k.is_neg())
+            add_lower_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
+        else
+            add_upper_bound_monic(non_fixed, bound_value.x / k, is_strict, lambda);
+    }
+}
+
+void core::propagate_monic_with_all_fixed(lpvar monic_var, const svector<lpvar>& vars, const rational& k)
+{
+    auto* lps = &lra;
+    auto lambda = [vars, lps]() { return lps->get_bound_constraint_witnesses_for_columns(vars); };
+    add_lower_bound_monic(monic_var, k, false, lambda);
+    add_upper_bound_monic(monic_var, k, false, lambda);
+}
+
+void core::add_bounds_for_zero_var(lpvar monic_var, lpvar zero_var)
+{
+    auto* lps = &lra;
+    auto lambda = [zero_var, lps]() {
+        return lps->get_bound_constraint_witnesses_for_column(zero_var);
+    };
+    TRACE("add_bound", lra.print_column_info(zero_var, tout) << std::endl;);
+    add_lower_bound_monic(monic_var, lp::mpq(0), false, lambda);
+    add_upper_bound_monic(monic_var, lp::mpq(0), false, lambda);
+}
+
+void core::calculate_implied_bounds_for_monic(lp::lpvar monic_var)
+{
+    lpvar non_fixed, zero_var;
+    const auto& vars = m_emons[monic_var].vars();
+    if (!is_linear(vars, zero_var, non_fixed))
+        return;
+
+    if (zero_var != null_lpvar)
+        add_bounds_for_zero_var(monic_var, zero_var);
+    else {
+        rational k = rational(1);
+        for (auto v : vars)
+            if (v != non_fixed) {
+                k *= val(v);
+                if (k.is_big()) return;
+            }
+
+        if (non_fixed != null_lpvar)
+            propagate_monic_with_non_fixed(monic_var, vars, non_fixed, k);
+        else  // all variables are fixed
+            propagate_monic_with_all_fixed(monic_var, vars, k);
+    }
+}
+
+void core::init_bound_propagation()
+{
+    this->m_implied_bounds.clear();
+    this->m_improved_lower_bounds.reset();
+    this->m_improved_upper_bounds.reset();
+    this->m_column_types = &lra.get_column_types();
+}
+
+}  // namespace nla
+
 

src/math/lp/nla_core.h

@@ -103,7 +103,10 @@ class core {
     emonics                  m_emons;
     svector<lpvar>           m_add_buffer;
     mutable indexed_uint_set m_active_var_set;
-
+    // these maps map a column index to the corresponding index in ibounds
+    u_map<unsigned>          m_improved_lower_bounds;
+    u_map<unsigned>          m_improved_upper_bounds;
+    const vector<lp::column_type>* m_column_types;
     reslimit                 m_nra_lim;
 
     bool                     m_use_nra_model = false;
@@ -114,12 +117,13 @@ class core {
 
     void check_weighted(unsigned sz, std::pair<unsigned, std::function<void(void)>>* checks);
     void add_bounds();
+    std_vector<lp::implied_bound> & m_implied_bounds;
     // try to improve bounds for variables in monomials.
     bool improve_bounds();
 
 public:    
     // constructor
-    core(lp::lar_solver& s, params_ref const& p, reslimit&);
+    core(lp::lar_solver& s, params_ref const& p, reslimit&, std_vector<lp::implied_bound> & implied_bounds);
     const auto& monics_with_changed_bounds() const { return m_monics_with_changed_bounds; }
     void reset_monics_with_changed_bounds() { m_monics_with_changed_bounds.reset(); }
     void insert_to_refine(lpvar j);
@@ -431,15 +435,23 @@ public:
     void set_use_nra_model(bool m);
     bool use_nra_model() const { return m_use_nra_model; }
     void collect_statistics(::statistics&);
+    bool is_linear(const svector<lpvar>& m, lpvar& zero_var, lpvar& non_fixed);
+    void add_bounds_for_zero_var(lpvar monic_var, lpvar zero_var);
+    void propagate_monic_with_non_fixed(lpvar monic_var, const svector<lpvar>& vars, lpvar non_fixed, const rational& k);
+    void propagate_monic_with_all_fixed(lpvar monic_var, const svector<lpvar>& vars, const rational& k);
+    void add_lower_bound_monic(lpvar j, const lp::mpq& v, bool is_strict, std::function<u_dependency*()> explain_dep);
+    void add_upper_bound_monic(lpvar j, const lp::mpq& v, bool is_strict, std::function<u_dependency*()> explain_dep);    
+    bool upper_bound_is_available(unsigned j) const;
+    bool lower_bound_is_available(unsigned j) const;
 private:
-    void restore_patched_values();
+    lp::column_type get_column_type(unsigned j) const { return (*m_column_types)[j]; }
     void constrain_nl_in_tableau();
     bool solve_tableau();
     void restore_tableau();
     void save_tableau();
     bool integrality_holds();
-
+    void calculate_implied_bounds_for_monic(lp::lpvar v);
-
+    void init_bound_propagation();    
 };  // end of core
 
 struct pp_mon {

src/math/lp/nla_solver.cpp

@@ -54,8 +54,8 @@ namespace nla {
         m_core->pop(n);
     }
     
-    solver::solver(lp::lar_solver& s, params_ref const& p, reslimit& limit): 
+    solver::solver(lp::lar_solver& s, params_ref const& p, reslimit& limit, std_vector<lp::implied_bound> & implied_bounds): 
-        m_core(alloc(core, s, p, limit)) {
+        m_core(alloc(core, s, p, limit, implied_bounds)) {
     }
     
     bool solver::influences_nl_var(lpvar j) const {    
@@ -88,6 +88,9 @@ namespace nla {
         m_core->collect_statistics(st);
     }
 
+    void solver::calculate_implied_bounds_for_monic(lp::lpvar v) {
+        m_core->calculate_implied_bounds_for_monic(v);
+    }
     // ensure r = x^y, add abstraction/refinement lemmas
     lbool solver::check_power(lpvar r, lpvar x, lpvar y, vector<lemma>& lemmas) {
         return m_core->check_power(r, x, y, lemmas);
@@ -97,4 +100,8 @@ namespace nla {
         m_core->check_bounded_divisions(lemmas);
     }
 
+    void solver::init_bound_propagation() {
+        m_core->init_bound_propagation();
+    }
+
 }

src/math/lp/nla_solver.h

@@ -24,7 +24,7 @@ namespace nla {
         core* m_core;
     public:
 
-        solver(lp::lar_solver& s, params_ref const& p, reslimit& limit);
+        solver(lp::lar_solver& s, params_ref const& p, reslimit& limit, std_vector<lp::implied_bound> & implied_bounds);
         ~solver();
         const auto& monics_with_changed_bounds() const { return m_core->monics_with_changed_bounds(); }
         void reset_monics_with_changed_bounds() { m_core->reset_monics_with_changed_bounds(); } 
@@ -48,5 +48,7 @@ namespace nla {
         nlsat::anum_manager& am();
         nlsat::anum const& am_value(lp::var_index v) const;
         void collect_statistics(::statistics & st);
+        void calculate_implied_bounds_for_monic(lp::lpvar v);
+        void init_bound_propagation();
     };
 }

src/sat/smt/arith_internalize.cpp

@@ -61,7 +61,7 @@ namespace arith {
 
     void solver::ensure_nla() {
         if (!m_nla) {
-            m_nla = alloc(nla::solver, *m_solver.get(), s().params(), m.limit());
+            m_nla = alloc(nla::solver, *m_solver.get(), s().params(), m.limit(), m_implied_bounds);
             for (auto const& _s : m_scopes) {
                 (void)_s;
                 m_nla->push();

src/smt/theory_lra.cpp

@@ -264,7 +264,7 @@ class theory_lra::imp {
 
     void ensure_nla() {
         if (!m_nla) {
-            m_nla = alloc(nla::solver, *m_solver.get(), ctx().get_params(), m.limit());
+            m_nla = alloc(nla::solver, *m_solver.get(), ctx().get_params(), m.limit(), m_implied_bounds);
             for (auto const& _s : m_scopes) {
                 (void)_s;
                 m_nla->push();
@@ -2198,13 +2198,10 @@ public:
             finish_bound_propagation();
     }
     
-    void calculate_implied_bounds_for_monic(lpvar monic_var, const svector<lpvar>& vars) {
-        m_bp.propagate_monic(monic_var, vars);
-    }
-    
     void propagate_bounds_for_touched_monomials() {
+        m_nla->init_bound_propagation();
         for (unsigned v : m_nla->monics_with_changed_bounds()) {
-            calculate_implied_bounds_for_monic(v, m_nla->get_core().emons()[v].vars());
+            m_nla->calculate_implied_bounds_for_monic(v);
         }
         m_nla->reset_monics_with_changed_bounds();
     }