diff --git a/src/sat/sat_aig_cuts.cpp b/src/sat/sat_aig_cuts.cpp
index 406f2f015..703ef00da 100644
--- a/src/sat/sat_aig_cuts.cpp
+++ b/src/sat/sat_aig_cuts.cpp
@@ -284,20 +284,11 @@ namespace sat {
         }
     }
 
-    void aig_cuts::add_node(literal head, bool_op op, unsigned sz, literal const* args) {
-        TRACE("aig_simplifier", tout << head << " == " << op << " " << literal_vector(sz, args) << "\n";);
-        unsigned v = head.var();
-        reserve(v);
-        unsigned offset = m_literals.size();
-        node n(head.sign(), op, sz, offset);
-        m_literals.append(sz, args);
-        if (op == and_op || op == xor_op) {
-            std::sort(m_literals.c_ptr() + offset, m_literals.c_ptr() + offset + sz);
-        }
-        for (unsigned i = 0; i < sz; ++i) {
-            reserve(args[i].var());
-            if (m_aig[args[i].var()].empty()) {
-                add_var(args[i].var());
+    void aig_cuts::add_node(bool_var v, node const& n) {
+        for (unsigned i = 0; i < n.size(); ++i) {
+            reserve(m_literals[i].var());
+            if (m_aig[m_literals[i].var()].empty()) {
+                add_var(m_literals[i].var());
             }
         }
         if (m_aig[v].empty() || n.is_const()) {
@@ -309,21 +300,44 @@ namespace sat {
                 augment_aig0(v, n, m_cuts[v]);
             }
             touch(v);
-            IF_VERBOSE(12, display(verbose_stream() << "add " << head.var() << " == ", n) << "\n");
-            
+            IF_VERBOSE(12, display(verbose_stream() << "add " << v << " == ", n) << "\n");            
         }
         else if (m_aig[v][0].is_const() || !insert_aux(v, n)) {
-            m_literals.shrink(m_literals.size() - sz);
+            m_literals.shrink(m_literals.size() - n.size());
             TRACE("aig_simplifier", tout << "duplicate\n";);
         }
         SASSERT(!m_aig[v].empty());
     }
 
+    void aig_cuts::add_node(bool_var v, uint64_t lut, unsigned sz, bool_var const* args) {
+        TRACE("aig_simplifier", tout << v << " == " << lut << " " << bool_var_vector(sz, args) << "\n";);
+        reserve(v);
+        unsigned offset = m_literals.size();
+        node n(lut, sz, offset);
+        for (unsigned i = 0; i < sz; ++i) {
+            m_literals.push_back(literal(args[i], false));
+        }
+        add_node(v, n);
+    }
+
+    void aig_cuts::add_node(literal head, bool_op op, unsigned sz, literal const* args) {
+        TRACE("aig_simplifier", tout << head << " == " << op << " " << literal_vector(sz, args) << "\n";);
+        unsigned v = head.var();
+        reserve(v);
+        unsigned offset = m_literals.size();
+        node n(head.sign(), op, sz, offset);
+        m_literals.append(sz, args);
+        if (op == and_op || op == xor_op) {
+            std::sort(m_literals.c_ptr() + offset, m_literals.c_ptr() + offset + sz);
+        }
+        add_node(v, n);
+    }
+
     void aig_cuts::add_cut(bool_var v, uint64_t lut, bool_var_vector const& args) {
         // args can be assumed to be sorted
         DEBUG_CODE(for (unsigned i = 0; i + 1 < args.size(); ++i) VERIFY(args[i] < args[i+1]););
-        reserve(v);
-        for (bool_var w : args) reserve(w); 
+        add_var(v);
+        for (bool_var w : args) add_var(w); 
         cut c;
         for (bool_var w : args) VERIFY(c.add(w));
         c.set_table(lut);
@@ -588,6 +602,7 @@ namespace sat {
         literal c, t, e;
         if (n.sign()) r.neg();
         m_clause.reset();
+        unsigned num_comb = 0;
         switch (n.op()) {
         case var_op:
             return;
@@ -623,15 +638,15 @@ namespace sat {
             m_clause.push_back(r, c, ~e);
             on_clause(m_clause);
             return;
-        case xor_op: {
+        case xor_op: 
             // r = a ^ b ^ c
             // <=>
             // ~r ^ a ^ b ^ c = 1
             if (n.size() > 10) {
                 throw default_exception("cannot handle large xors");
             }
-            unsigned num_comp = (1 << n.size());
-            for (unsigned i = 0; i < num_comp; ++i) {
+            num_comb = (1 << n.size());
+            for (unsigned i = 0; i < num_comb; ++i) {
                 bool parity = n.size() % 2 == 1;
                 m_clause.reset();
                 for (unsigned j = 0; j < n.size(); ++j) {
@@ -649,7 +664,21 @@ namespace sat {
                 on_clause(m_clause);
             }
             return;
-        }
+        case lut_op: 
+            // r = LUT(v0, v1, v2)
+            num_comb = (1 << n.size());
+            for (unsigned i = 0; i < num_comb; ++i) {
+                m_clause.reset();
+                for (unsigned j = 0; j < n.size(); ++j) {
+                    literal lit = m_literals[n.offset() + j];
+                    if (0 != (i & (1 << j))) lit.neg();
+                    m_clause.push_back(lit);
+                }
+                m_clause.push_back(0 == (n.lut() & (1ull << i)) ? ~r : r);
+                TRACE("aig_simplifier", tout << n.lut() << " " <<  m_clause << "\n";);
+                on_clause(m_clause);
+            }
+            return;
         default:
             UNREACHABLE();
             break;
diff --git a/src/sat/sat_aig_cuts.h b/src/sat/sat_aig_cuts.h
index c74923209..c7ca473a0 100644
--- a/src/sat/sat_aig_cuts.h
+++ b/src/sat/sat_aig_cuts.h
@@ -82,7 +82,7 @@ namespace sat {
             explicit node(bool sign, bool_op op, unsigned nc, unsigned o) : 
                 m_sign(sign), m_op(op), m_size(nc), m_offset(o) {}
             explicit node(uint64_t lut, unsigned nc, unsigned o):
-                m_sign(false), m_op(lut_op), m_size(nc), m_offset(o) {}
+                m_sign(false), m_op(lut_op), m_lut(lut), m_size(nc), m_offset(o) {}
             bool is_valid() const { return m_offset != UINT_MAX; }
             bool_op op() const { return m_op; }
             bool is_var() const { return m_op == var_op; }
@@ -165,11 +165,13 @@ namespace sat {
         void validate_aig2(cut const& a, cut const& b, unsigned v, node const& n, cut const& c);
         void validate_aigN(unsigned v, node const& n, cut const& c); 
 
+        void add_node(bool_var v, node const& n);
     public:
 
         aig_cuts();
         void add_var(unsigned v);
         void add_node(literal head, bool_op op, unsigned sz, literal const* args);
+        void add_node(bool_var head, uint64_t lut, unsigned sz, bool_var const* args);
         void add_cut(bool_var v, uint64_t lut, bool_var_vector const& args);
         void set_root(bool_var v, literal r);
 
diff --git a/src/sat/sat_aig_simplifier.cpp b/src/sat/sat_aig_simplifier.cpp
index 57d71e803..69f256912 100644
--- a/src/sat/sat_aig_simplifier.cpp
+++ b/src/sat/sat_aig_simplifier.cpp
@@ -237,7 +237,8 @@ namespace sat {
             std::function<void(uint64_t, bool_var_vector const&, bool_var)> on_lut = 
                 [&,this](uint64_t lut, bool_var_vector const& vars, bool_var v) {
                 m_stats.m_xluts++;
-                m_aig_cuts.add_cut(v, lut, vars);
+                // m_aig_cuts.add_cut(v, lut, vars);
+                m_aig_cuts.add_node(v, lut, vars.size(), vars.c_ptr());
             };
             lut_finder lf(s);
             lf.set(on_lut);
diff --git a/src/sat/sat_lut_finder.cpp b/src/sat/sat_lut_finder.cpp
index 11783eba8..2ee06034e 100644
--- a/src/sat/sat_lut_finder.cpp
+++ b/src/sat/sat_lut_finder.cpp
@@ -113,12 +113,11 @@ namespace sat {
         m_removed_clauses.append(m_clauses_to_remove);
         bool_var v;
         uint64_t lut = convert_combination(m_vars, v);
-        IF_VERBOSE(12, 
-                   for (clause* cp : m_clauses_to_remove) {
-                       verbose_stream() << *cp << "\n";
-                       verbose_stream() << v << ": " << m_vars << "\n";
-                   }
-                   display_mask(verbose_stream(), lut, 1u << m_vars.size()) << "\n";);
+        TRACE("aig_simplifier",
+              for (clause* cp : m_clauses_to_remove) {
+                  tout << *cp << "\n" << v << ": " << m_vars << "\n";
+              }
+              display_mask(tout, lut, 1u << m_vars.size()) << "\n";);
         m_on_lut(lut, m_vars, v);
     }