add new polynomials from handle_nullified to m_todo

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

src/nlsat/levelwise.cpp

@@ -1217,12 +1217,18 @@ namespace nlsat {
             // Line 10/11: detect nullification + pick a non-zero coefficient witness per p.
             m_witnesses.clear();
             m_witnesses.reserve(m_level_ps.size());
-            for (unsigned i = 0; i < m_level_ps.size(); ++i) {
+            // Fixpoint loop: handle_nullified_poly may add more polynomials back at m_level
+            // via request_factorized. Drain them from m_todo into m_level_ps and
+            // compute witnesses for the new entries until no more appear.
+            for (unsigned i = 0; i < m_level_ps.size(); i++) {
                 polynomial_ref p(m_level_ps.get(i), m_pm);
                 polynomial_ref w = choose_nonzero_coeff(p, m_level);
                 if (!w)
                     handle_nullified_poly(p);
                 m_witnesses.push_back(w);
+                // Absorb any same-level polys that handle_nullified_poly added to m_todo
+                if (i + 1 == m_level_ps.size())
+                    m_todo.extract_polys_at_level(m_level, m_level_ps);
             }
         }
 

src/nlsat/nlsat_common.cpp

@@ -112,6 +112,27 @@ namespace nlsat {
         return x;
     }
 
+    unsigned todo_set::extract_polys_at_level(var x, polynomial_ref_vector& out) {
+        pmanager& pm = m_set.m();
+        unsigned sz = m_set.size();
+        unsigned j = 0;
+        unsigned count = 0;
+        for (unsigned i = 0; i < sz; i++) {
+            poly* p = m_set.get(i);
+            if (pm.max_var(p) == x) {
+                out.push_back(p);
+                m_in_set[pm.id(p)] = false;
+                ++count;
+            }
+            else {
+                m_set.set(j, p);
+                j++;
+            }
+        }
+        m_set.shrink(j);
+        return count;
+    }
+
     /**
        \brief Wrapper for factorization
     */

src/nlsat/nlsat_common.h

@@ -44,6 +44,9 @@ namespace nlsat {
            them in max_polys. Return the maximal variable
          */
         var extract_max_polys(polynomial_ref_vector& max_polys);
+        // Extract polynomials whose max_var equals \c x, appending them to \c out.
+        // Returns the number of polynomials extracted.
+        unsigned extract_polys_at_level(var x, polynomial_ref_vector& out);
     };
 
     inline std::ostream& display(std::ostream& out, pmanager& pm, polynomial_ref const& p, display_var_proc const& proc) {