diff --git a/src/Makefile b/src/Makefile
index 5f3b9bc..c1cbf73 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,5 +1,5 @@
-CFLAGS=-O2 -g -std=gnu++11
-LDFLAGS=
+CFLAGS=-O2 -g -std=gnu++11 -fvisibility=hidden -fpic
+LDFLAGS=-fvisibility=hidden -Wl,--export-dynamic -fpic
 
 CC=g++
 
diff --git a/src/arifmetic.cpp b/src/arifmetic.cpp
new file mode 100644
index 0000000..ba34354
--- /dev/null
+++ b/src/arifmetic.cpp
@@ -0,0 +1,148 @@
+#include <math.h>
+#include "object.h"
+
+ObjectBase* Arifm_Add(ObjectList* input)
+{
+ if(input->Size()!=2) return 0;
+ std::type_index t1(typeid(*input->At(0))),t2(typeid(*input->At(1)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ if( (t1!=tr && t1!=ti) || (t2!=tr && t2!=ti) ) return 0;
+
+ // Integer arifmetic
+ if(t1==ti && t2==ti) return new ObjectInt(dynamic_cast<const ObjectInt*>(input->At(0))->Value() + dynamic_cast<const ObjectInt*>(input->At(1))->Value());
+
+ // Real arifmetic
+ double r1,r2;
+
+ if(t1==tr) r1=dynamic_cast<const ObjectReal*>(input->At(0))->Value();
+ else r1=dynamic_cast<const ObjectInt*>(input->At(0))->Value();
+
+ if(t2==tr) r2=dynamic_cast<const ObjectReal*>(input->At(1))->Value();
+ else r2=dynamic_cast<const ObjectInt*>(input->At(1))->Value();
+
+ return new ObjectReal(r1+r2);
+}
+
+
+ObjectBase* Arifm_Sub(ObjectList* input)
+{
+ if(input->Size()!=2) return 0;
+ std::type_index t1(typeid(*input->At(0))),t2(typeid(*input->At(1)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ if( (t1!=tr && t1!=ti) || (t2!=tr && t2!=ti) ) return 0;
+
+ // Integer arifmetic
+ if(t1==ti && t2==ti) return new ObjectInt(dynamic_cast<const ObjectInt*>(input->At(0))->Value() - dynamic_cast<const ObjectInt*>(input->At(1))->Value());
+
+ // Real arifmetic
+ double r1,r2;
+
+ if(t1==tr) r1=dynamic_cast<const ObjectReal*>(input->At(0))->Value();
+ else r1=dynamic_cast<const ObjectInt*>(input->At(0))->Value();
+
+ if(t2==tr) r2=dynamic_cast<const ObjectReal*>(input->At(1))->Value();
+ else r2=dynamic_cast<const ObjectInt*>(input->At(1))->Value();
+
+ return new ObjectReal(r1-r2);
+}
+
+
+ObjectBase* Arifm_Mul(ObjectList* input)
+{
+ if(input->Size()!=2) return 0;
+ std::type_index t1(typeid(*input->At(0))),t2(typeid(*input->At(1)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ if( (t1!=tr && t1!=ti) || (t2!=tr && t2!=ti) ) return 0;
+
+ // Integer arifmetic
+ if(t1==ti && t2==ti) return new ObjectInt(dynamic_cast<const ObjectInt*>(input->At(0))->Value() * dynamic_cast<const ObjectInt*>(input->At(1))->Value());
+
+ // Real arifmetic
+ double r1,r2;
+
+ if(t1==tr) r1=dynamic_cast<const ObjectReal*>(input->At(0))->Value();
+ else r1=dynamic_cast<const ObjectInt*>(input->At(0))->Value();
+
+ if(t2==tr) r2=dynamic_cast<const ObjectReal*>(input->At(1))->Value();
+ else r2=dynamic_cast<const ObjectInt*>(input->At(1))->Value();
+
+ return new ObjectReal(r1*r2);
+}
+
+
+ObjectBase* Arifm_Div(ObjectList* input)
+{
+ if(input->Size()!=2) return 0;
+ std::type_index t1(typeid(*input->At(0))),t2(typeid(*input->At(1)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ if( (t1!=tr && t1!=ti) || (t2!=tr && t2!=ti) ) return 0;
+
+ // Integer arifmetic
+ if(t1==ti && t2==ti) return new ObjectInt(dynamic_cast<const ObjectInt*>(input->At(0))->Value() / dynamic_cast<const ObjectInt*>(input->At(1))->Value());
+
+ // Real arifmetic
+ double r1,r2;
+
+ if(t1==tr) r1=dynamic_cast<const ObjectReal*>(input->At(0))->Value();
+ else r1=dynamic_cast<const ObjectInt*>(input->At(0))->Value();
+
+ if(t2==tr) r2=dynamic_cast<const ObjectReal*>(input->At(1))->Value();
+ else r2=dynamic_cast<const ObjectInt*>(input->At(1))->Value();
+
+ return new ObjectReal(r1/r2);
+}
+
+
+ObjectBase* Arifm_Pow(ObjectList* input)
+{
+ if(input->Size()!=2) return 0;
+ std::type_index t1(typeid(*input->At(0))),t2(typeid(*input->At(1)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ if( (t1!=tr && t1!=ti) || (t2!=tr && t2!=ti) ) return 0;
+
+ // Only real arifmetic
+ double r1,r2;
+
+ if(t1==tr) r1=dynamic_cast<const ObjectReal*>(input->At(0))->Value();
+ else r1=dynamic_cast<const ObjectInt*>(input->At(0))->Value();
+
+ if(t2==tr) r2=dynamic_cast<const ObjectReal*>(input->At(1))->Value();
+ else r2=dynamic_cast<const ObjectInt*>(input->At(1))->Value();
+
+ return new ObjectReal(pow(r1,r2));
+}
+
+
+ObjectBase* Arifm_Neg(ObjectList* input)
+{
+ if(input->Size()!=1) return 0;
+ std::type_index t(typeid(*input->At(0)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ // Integer arifmetic
+ if(t==ti) return new ObjectInt(-dynamic_cast<const ObjectInt*>(input->At(0))->Value());
+ // Real arifmetic
+ if(t==tr) return new ObjectReal(-dynamic_cast<const ObjectReal*>(input->At(0))->Value());
+
+ return 0;
+}
+
+
+ObjectBase* Arifm_Pos(ObjectList* input)
+{
+ if(input->Size()!=1) return 0;
+ std::type_index t(typeid(*input->At(0)));
+ std::type_index tr(typeid(ObjectReal)),ti(typeid(ObjectInt));
+
+ // Integer arifmetic
+ if(t==ti) return new ObjectInt(dynamic_cast<const ObjectInt*>(input->At(0))->Value());
+ // Real arifmetic
+ if(t==tr) return new ObjectReal(dynamic_cast<const ObjectReal*>(input->At(0))->Value());
+
+ return 0;
+}
\ No newline at end of file
diff --git a/src/arifmetic.h b/src/arifmetic.h
new file mode 100644
index 0000000..9fd4b5c
--- /dev/null
+++ b/src/arifmetic.h
@@ -0,0 +1,9 @@
+#include "object.h"
+
+ObjectBase* Arifm_Add(ObjectList* input);
+ObjectBase* Arifm_Sub(ObjectList* input);
+ObjectBase* Arifm_Mul(ObjectList* input);
+ObjectBase* Arifm_Div(ObjectList* input);
+ObjectBase* Arifm_Pow(ObjectList* input);
+ObjectBase* Arifm_Neg(ObjectList* input);
+ObjectBase* Arifm_Pos(ObjectList* input);
\ No newline at end of file
diff --git a/src/common.h b/src/common.h
new file mode 100644
index 0000000..6e7b27e
--- /dev/null
+++ b/src/common.h
@@ -0,0 +1,6 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+#define EXPORT __attribute__ ((visibility ("default")))
+
+#endif
\ No newline at end of file
diff --git a/src/debug.h b/src/debug.h
index b5f6896..76803b4 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -1,10 +1,13 @@
 #ifndef DEBUG_H
 #define DEBUG_H
 #include <iostream>
+#include "common.h"
 
 enum debug_level {INTERNALREQUEST,MOREDEBUG,DEBUG,INFO,WARNING,ERROR};
 
-std::ostream& COUT(debug_level dl);
+extern "C" {
+EXPORT std::ostream& COUT(debug_level dl);
+}
 
 debug_level SetDebugLevel(debug_level dl=INTERNALREQUEST);
 
diff --git a/src/globals.cpp b/src/globals.cpp
index c5031db..47d79e4 100644
--- a/src/globals.cpp
+++ b/src/globals.cpp
@@ -22,3 +22,8 @@ void ClearGlobals()
  G_tosave.clear();
  G_toprint.clear();
 }
+
+void RegisterFunction(const std::string& name, Func func)
+{
+ G_funcs.emplace(name,func);
+}
\ No newline at end of file
diff --git a/src/globals.h b/src/globals.h
index c468ec9..76c296a 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -6,17 +6,21 @@
 #include "object.h"
 
 // Variables definitions
-extern std::map<std::string,ObjectBase*> G_vars;
+extern EXPORT std::map<std::string,ObjectBase*> G_vars;
 
 // Functions addresses
 typedef ObjectBase* (*Func)(ObjectList*);
-extern std::multimap<std::string,Func> G_funcs;
+extern EXPORT std::multimap<std::string,Func> G_funcs;
 
 // List of objects to save
-extern std::list<ObjectBase*> G_tosave;
+extern EXPORT std::list<ObjectBase*> EXPORT G_tosave;
 
 // List of objects to print
-extern std::list<ObjectBase*> G_toprint;
+extern EXPORT std::list<ObjectBase*> EXPORT G_toprint;
 
 void ClearGlobals();
+
+extern "C" {
+EXPORT void RegisterFunction(const std::string& name, Func func);
+}
 #endif
diff --git a/src/init.cpp b/src/init.cpp
index 11d57e3..4a7ae58 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -2,6 +2,8 @@
 #include "init.h"
 #include "debug.h"
 #include "object.h"
+#include "globals.h"
+#include "arifmetic.h"
 #include "parser/parser.h"
 #include "parser/grammatical.h"
 #include "parser/lexical.h"
@@ -11,6 +13,7 @@ int ParseConfigFile(char* config)
  yyscan_t scanner;
  struct lexical_extra extra;
  FILE* conffd;
+ int ret;
 
  conffd=fopen(config,"r");
  if(conffd==0)
@@ -26,8 +29,21 @@ int ParseConfigFile(char* config)
  conflex_init_extra(&extra,&scanner);
  confset_in(conffd,scanner);
 // {YYSTYPE qqq; while(conflex(&qqq,scanner)>0);}
- confparse(scanner);
+ ret=confparse(scanner);
  conflex_destroy(scanner);
  fclose(conffd);
+ return ret;
+}
+
+
+int RegisterArifmeticFunctions()
+{
+ RegisterFunction("ADD",Arifm_Add);
+ RegisterFunction("SUB",Arifm_Sub);
+ RegisterFunction("MUL",Arifm_Mul);
+ RegisterFunction("DIV",Arifm_Div);
+ RegisterFunction("POW",Arifm_Pow);
+ RegisterFunction("POS",Arifm_Pos);
+ RegisterFunction("NEG",Arifm_Neg);
  return 0;
 }
diff --git a/src/init.h b/src/init.h
index 539ba37..10b2e51 100644
--- a/src/init.h
+++ b/src/init.h
@@ -6,5 +6,6 @@ typedef void* yyscan_t;
 #endif
 
 int ParseConfigFile(char* config);
+int RegisterArifmeticFunctions();
 
 #endif
diff --git a/src/main.cpp b/src/main.cpp
index ea540b1..3efaf9f 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -5,10 +5,15 @@
 int main(int argc, char** argv)
 {
  if(argc!=2) return 1;
+ int ret;
 
  SetDebugLevel(INFO);
 
- ParseConfigFile(argv[1]);
+ COUT(INFO)<<"Parse config file "<<argv[1]<<" ";
+ ret=ParseConfigFile(argv[1]); if(ret!=0) return 1;
+ COUT(INFO)<<"Ok"<<std::endl;
+
+ RegisterArifmeticFunctions();
 
  COUT(INFO)<<G_vars.size()<<std::endl;
  for(auto& i: G_vars) COUT(INFO)<<i.first<<"="+i.second->Dump()<<";"<<std::endl;
diff --git a/src/object.cpp b/src/object.cpp
index bb9a7ae..8c91507 100644
--- a/src/object.cpp
+++ b/src/object.cpp
@@ -1,6 +1,6 @@
 #include "object.h"
 
-template<> std::string ObjectSimple<bool>::type="bool";
-template<> std::string ObjectSimple<int64_t>::type="integer";
-template<> std::string ObjectSimple<double>::type="real";
-template<> std::string ObjectSimple<std::string>::type="string";
+template<> EXPORT std::string ObjectSimple<bool>::type="bool";
+template<> EXPORT std::string ObjectSimple<int64_t>::type="integer";
+template<> EXPORT std::string ObjectSimple<double>::type="real";
+template<> EXPORT std::string ObjectSimple<std::string>::type="string";
diff --git a/src/object.h b/src/object.h
index 7ce27ee..bde6f5d 100644
--- a/src/object.h
+++ b/src/object.h
@@ -4,7 +4,7 @@
 #include <errno.h>
 #include <string.h>
 #include <inttypes.h>
-#include <list>
+#include <vector>
 #include <sstream>
 #include <typeinfo>
 #include <typeindex>
@@ -14,7 +14,7 @@
 #define IS_OTYPE(quo,equ) (std::type_index(typeid(*quo))==std::type_index(typeid(equ)))
 
 // Base class for all objects
-class ObjectBase
+class EXPORT ObjectBase
 {
 protected:
 // No save by default
@@ -68,7 +68,7 @@ public:
 
 // Template for objects without specific constructor/destructor
 template<class T>
-class ObjectSimple: public ObjectBase
+class EXPORT ObjectSimple: public ObjectBase
 {
 private:
  T val;
@@ -118,7 +118,7 @@ inline const int8_t* ObjectSimple<std::string>::Blob(size_t* size) const
 }
 
 // Class for name-value pair
-class ObjectPair: public ObjectBase
+class EXPORT ObjectPair: public ObjectBase
 {
 private:
  std::string name;
@@ -151,10 +151,10 @@ public:
 };
 
 // Class for objects list
-class ObjectList: public ObjectBase
+class EXPORT ObjectList: public ObjectBase
 {
 private:
- std::list<ObjectBase*> vals;
+ std::vector<ObjectBase*> vals;
 
 public:
  ObjectList() {}
@@ -173,10 +173,10 @@ public:
   COUT(INFO)<<"Number of elements: "<<Size()<<std::endl;
   return true;
  }
- std::list<ObjectBase*>::size_type Size() const {return vals.size();}
+ std::vector<ObjectBase*>::size_type Size() const {return vals.size();}
  std::string Type() const override {return "list";}
- ObjectList* PushFront(ObjectBase* p) {vals.push_front(p); return this;}
  ObjectList* PushBack(ObjectBase* p) {vals.push_back(p); return this;}
+ const ObjectBase* At(std::vector<ObjectBase*>::size_type i) const {return vals[i];}
  std::string Dump() const override
  {
   std::string s("(");