bugfixes

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/math/dd/dd_pdd.cpp

@@ -1860,6 +1860,22 @@ namespace dd {
         return (*this) * rational::power_of_two(n);
     }
 
+    bool pdd::has_unit(pdd& x, pdd& rest) const {
+        if (is_val())
+            return false;
+        pdd r = *this;
+        while (!r.is_val()) {
+            if (r.hi().is_one()) {
+                x = m->mk_var(r.var());
+                rest = *this - x;
+                return true;
+            }
+            r = r.lo();
+        }
+        return false;
+    }
+
+
     /**
      * \brief substitute variable v by r.
      * This base line implementation is simplistic and does not use operator caching.

src/math/dd/dd_pdd.h

@@ -441,6 +441,7 @@ namespace dd {
         bool is_unary() const { return !is_val() && lo().is_zero() && hi().is_val(); }
         bool is_offset() const { return !is_val() && lo().is_val() && hi().is_one(); }
         bool is_binary() const { return m->is_binary(root); }
+        bool has_unit(pdd& x, pdd& rest) const; 
         bool is_monomial() const { return m->is_monomial(root); }
         bool is_univariate() const { return m->is_univariate(root); }
         bool is_univariate_in(unsigned v) const { return m->is_univariate_in(root, v); }

src/math/lp/int_solver.cpp

@@ -950,14 +950,16 @@ namespace lp {
             bool feas = _check_feasible();
             lra.pop(1);
 
-            if (settings().get_cancel_flag())
-                return lia_move::undef;
-
-            if (!feas)
-                return lia_move::conflict;
-            
+            if (!feas) {
+                for (auto const& cut : cuts)
+                    if (!is_small_cut(cut))
+                        add_cut(cut);
+            }            
         }
 
+        if (settings().get_cancel_flag())
+            return lia_move::undef;
+
         if (!_check_feasible())
             return lia_move::conflict;