Limit visibility of some implementation methods

Author: NlightNFotis

src/solvers/sat/cnf.h

@@ -42,6 +42,7 @@ class cnft:public propt
   virtual void set_no_variables(size_t no) { _no_variables=no; }
   virtual size_t no_clauses() const=0;
 
+protected:
   void gate_and(literalt a, literalt b, literalt o);
   void gate_or(literalt a, literalt b, literalt o);
   void gate_xor(literalt a, literalt b, literalt o);
@@ -52,7 +53,6 @@ class cnft:public propt
 
   static bvt eliminate_duplicates(const bvt &);
 
-protected:
   size_t _no_variables;
 
   bool process_clause(const bvt &bv, bvt &dest);