diff --git a/src/math/simplex/sparse_matrix.h b/src/math/simplex/sparse_matrix.h
index cfe146b84..1c9f0fde8 100644
--- a/src/math/simplex/sparse_matrix.h
+++ b/src/math/simplex/sparse_matrix.h
@@ -102,7 +102,7 @@ namespace simplex {
             void compress(manager& m, vector<column> & cols); 
             void compress_if_needed(manager& m, vector<column> & cols);
             void save_var_pos(svector<int> & result_map, unsigned_vector& idxs) const;
-            bool is_coeff_of(var_t v, numeral const & expected) const;
+            //bool is_coeff_of(var_t v, numeral const & expected) const;
             int get_idx_of(var_t v) const;
         };
         
@@ -123,7 +123,7 @@ namespace simplex {
             void reset();
             void compress(vector<_row> & rows);
             void compress_if_needed(vector<_row> & rows);
-            void compress_singleton(vector<_row> & rows, unsigned singleton_pos);
+            //void compress_singleton(vector<_row> & rows, unsigned singleton_pos);
             col_entry const * get_first_col_entry() const;
             col_entry & add_col_entry(int & pos_idx);
             void del_col_entry(unsigned idx);
diff --git a/src/math/simplex/sparse_matrix_def.h b/src/math/simplex/sparse_matrix_def.h
index 561025303..277165138 100644
--- a/src/math/simplex/sparse_matrix_def.h
+++ b/src/math/simplex/sparse_matrix_def.h
@@ -205,6 +205,7 @@ namespace simplex {
         }
     }
 
+#if 0
     /**
        \brief Special version of compress, that is used when the column contain
        only one entry located at position singleton_pos.
@@ -221,7 +222,7 @@ namespace simplex {
         m_first_free_idx = -1;
         m_entries.shrink(1);
     }
-    
+#endif
     template<typename Ext>
     const typename sparse_matrix<Ext>::col_entry * 
     sparse_matrix<Ext>::column::get_first_col_entry() const {
diff --git a/src/smt/theory_diff_logic.cpp b/src/smt/theory_diff_logic.cpp
index fd5bbd5da..f1f00833b 100644
--- a/src/smt/theory_diff_logic.cpp
+++ b/src/smt/theory_diff_logic.cpp
@@ -21,6 +21,7 @@ Revision History:
 
 #include"rational.h"
 #include"theory_diff_logic_def.h"
+#include"sparse_matrix_def.h"
 
 namespace smt {
 
@@ -34,5 +35,5 @@ template class theory_diff_logic<srdl_ext>;
 
 namespace simplex {
 template class simplex<mpq_ext>;
-
+template class sparse_matrix<mpq_ext>;
 };