start porting grobner basis functionality

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>

src/math/lp/nla_grobner.cpp

@@ -0,0 +1,104 @@
+/*++
+  Copyright (c) 2017 Microsoft Corporation
+
+  Module Name:
+
+  <name>
+
+  Abstract:
+
+  <abstract>
+
+  Author:
+  Nikolaj Bjorner (nbjorner)
+  Lev Nachmanson (levnach)
+
+  Revision History:
+
+
+  --*/
+#include "math/lp/nla_grobner.h"
+#include "math/lp/nla_core.h"
+#include "math/lp/factorization_factory_imp.h"
+namespace nla {
+nla_grobner::nla_grobner(core *c) : common(c) {}
+
+void nla_grobner::add_var_and_its_factors_to_q_and_collect_new_rows(lpvar j, std::queue<lpvar> & q) {
+    SASSERT(m_active_vars.contains(j) == false);
+    const auto& matrix = c().m_lar_solver.A_r();
+    m_active_vars.insert(j);
+    for (auto & s : matrix.m_columns[j]) {
+        unsigned row = s.var();
+        if (m_rows.contains(row)) continue;
+        m_rows.insert(row);
+        for (auto& rc : matrix.m_rows[row]) {
+            if (m_active_vars.contains(rc.var()))
+                continue;
+            q.push(rc.var());
+        }
+    }
+
+    if (!c().is_monomial_var(j))
+        return;
+
+    const monomial& m = c().emons()[j];
+    for (auto fcn : factorization_factory_imp(m, c())) {
+        for (const factor& fc: fcn) {
+            lpvar j = var(fc);
+            if (! m_active_vars.contains(j))
+                add_var_and_its_factors_to_q_and_collect_new_rows(j, q);
+        }
+    }            
+}
+    
+
+void nla_grobner::find_rows() {
+    prepare_rows_and_active_vars();
+    std::queue<lpvar> q;
+    for (lpvar j : c().m_to_refine) {        
+        TRACE("nla_grobner", c().print_monomial(c().emons()[j], tout) << "\n";);
+        q.push(j);
+    }
+
+    while (!q.empty()) {
+        unsigned j = q.front();        
+        q.pop();
+        if (m_active_vars.contains(j))
+            continue;
+        add_var_and_its_factors_to_q_and_collect_new_rows(j, q);
+    }
+    
+
+}
+
+void nla_grobner::prepare_rows_and_active_vars() {
+    m_rows.clear();
+    m_rows.resize(c().m_lar_solver.row_count());
+    m_active_vars.clear();
+    m_active_vars.resize(c().m_lar_solver.column_count());
+}
+
+void nla_grobner::grobner_lemmas() {
+    c().lp_settings().st().m_grobner_calls++;
+    if (c().lp_settings().st().m_grobner_calls == 2)
+        SASSERT(false);
+
+
+    find_rows();
+
+    TRACE("nla_grobner",
+          {
+              const auto& matrix = c().m_lar_solver.A_r();
+          tout << "rows = " << m_rows.size() << "\n";
+          for (unsigned k : m_rows) {
+              c().print_term(matrix.m_rows[k], tout) << "\n";
+          }
+          tout << "the matrix =\n";
+          
+          for (const auto & r : matrix.m_rows) {
+              c().print_term(r, tout) << "\n";
+          }
+          }
+          );
+}
+} // end of nla namespace