diff --git a/examples/exMathInterpreter.cpp b/examples/exMathInterpreter.cpp
index 0374c1d..c74797d 100644
--- a/examples/exMathInterpreter.cpp
+++ b/examples/exMathInterpreter.cpp
@@ -21,7 +21,7 @@ int main(int argc, char* argv[])
     RunContext context;
     
     cout << "-- Source code:" << endl << source << endl << endl;
-    interpreter.compile();
+    interpreter.compile(context);
     cout << "-- Abstract Syntax Tree:" << endl;
     if (interpreter.getAST())
     {
@@ -32,7 +32,18 @@ int main(int argc, char* argv[])
         cout << "<null>" << endl << endl;
     }
     cout << "-- Program:" << endl << interpreter << endl;
-    StdMath::addStdMathFunc(context.fTable);
+    cout << "-- Variable table:" << endl;
+    for (auto &v: context.vTable)
+    {
+        cout << "'" << v.first << "': " << v.second << endl;
+    }
+    cout << endl;
+    cout << "-- Function table:" << endl;
+    for (auto &f: context.fTable)
+    {
+        cout << "'" << f.first << "': " << f.second << endl;
+    }
+    cout << endl;
     interpreter(context);
     if (!context.dStack.empty())
     {
diff --git a/lib/CompiledFunction.cpp b/lib/CompiledFunction.cpp
index bdf3776..b8181b8 100644
--- a/lib/CompiledFunction.cpp
+++ b/lib/CompiledFunction.cpp
@@ -44,7 +44,23 @@ void CompiledDoubleFunction::setCode(const string &code)
 {
     interpreter_.reset(new MathInterpreter(code));
     context_.reset(new RunContext);
-    StdMath::addStdMathFunc(context_->fTable);
+    varAddress_.reset(new std::vector<unsigned int>);
+    isCompiled_.reset(new bool(false));
+}
+
+// compile /////////////////////////////////////////////////////////////////////
+void CompiledDoubleFunction::compile(void) const
+{
+    if (!*isCompiled_)
+    {
+        interpreter_->compile(*(context_));
+        varAddress_->clear();
+        for (Index i = 0; i < getNArg(); ++i)
+        {
+            varAddress_->push_back(context_->vTable.at("x_" + strFrom(i)));
+        }
+        *isCompiled_ = true;
+    }
 }
 
 // function call ///////////////////////////////////////////////////////////////
@@ -52,9 +68,10 @@ double CompiledDoubleFunction::operator()(const double *arg) const
 {
     double result;
     
-    for (Index i = 0; i < getNArg(); ++i)
+    compile();
+    for (unsigned int i = 0; i < getNArg(); ++i)
     {
-        context_->vTable["x_" + strFrom(i)] = arg[i];
+        context_->vMem[(*varAddress_)[i]] = arg[i];
     }
     (*interpreter_)(*context_);
     if (!context_->dStack.empty())
@@ -74,7 +91,7 @@ double CompiledDoubleFunction::operator()(const double *arg) const
 // IO //////////////////////////////////////////////////////////////////////////
 ostream & Latan::operator<<(ostream &out, CompiledDoubleFunction &f)
 {
-    f.interpreter_->compile();
+    f.compile();
     out << *(f.interpreter_);
     
     return out;
diff --git a/lib/CompiledFunction.hpp b/lib/CompiledFunction.hpp
index 9a1b532..4bbdb2f 100644
--- a/lib/CompiledFunction.hpp
+++ b/lib/CompiledFunction.hpp
@@ -46,8 +46,13 @@ public:
     friend std::ostream & operator<<(std::ostream &out,
                                      CompiledDoubleFunction &f);
 private:
-    std::shared_ptr<MathInterpreter> interpreter_;
-    std::shared_ptr<RunContext>      context_;
+    // compile
+    void compile(void) const;
+private:
+    std::shared_ptr<MathInterpreter>           interpreter_;
+    std::shared_ptr<RunContext>                context_;
+    std::shared_ptr<std::vector<unsigned int>> varAddress_;
+    std::shared_ptr<bool>                      isCompiled_;
 };
 
 std::ostream & operator<<(std::ostream &out, CompiledDoubleFunction &f);
diff --git a/lib/CompiledModel.cpp b/lib/CompiledModel.cpp
index d3e104a..d4052b8 100644
--- a/lib/CompiledModel.cpp
+++ b/lib/CompiledModel.cpp
@@ -46,7 +46,29 @@ void CompiledDoubleModel::setCode(const std::string &code)
 {
     interpreter_.reset(new MathInterpreter(code));
     context_.reset(new RunContext);
-    StdMath::addStdMathFunc(context_->fTable);
+    varAddress_.reset(new std::vector<unsigned int>);
+    parAddress_.reset(new std::vector<unsigned int>);
+    isCompiled_.reset(new bool(false));
+}
+
+// compile /////////////////////////////////////////////////////////////////////
+void CompiledDoubleModel::compile(void) const
+{
+    if (!*isCompiled_)
+    {
+        interpreter_->compile(*(context_));
+        varAddress_->clear();
+        parAddress_->clear();
+        for (Index i = 0; i < getNArg(); ++i)
+        {
+            varAddress_->push_back(context_->vTable.at("x_" + strFrom(i)));
+        }
+        for (Index j = 0; j < getNPar(); ++j)
+        {
+            parAddress_->push_back(context_->vTable.at("p_" + strFrom(j)));
+        }
+        *isCompiled_ = true;
+    }
 }
 
 // function call ///////////////////////////////////////////////////////////////
@@ -55,13 +77,14 @@ double CompiledDoubleModel::operator()(const double *arg,
 {
     double result;
     
-    for (Index i = 0; i < getNArg(); ++i)
+    compile();
+    for (unsigned int i = 0; i < getNArg(); ++i)
     {
-        context_->vTable["x_" + strFrom(i)] = arg[i];
+        context_->vMem[(*varAddress_)[i]] = arg[i];
     }
-    for (Index j = 0; j < getNPar(); ++j)
+    for (unsigned int j = 0; j < getNPar(); ++j)
     {
-        context_->vTable["p_" + strFrom(j)] = par[j];
+        context_->vMem[(*parAddress_)[j]] = par[j];
     }
     (*interpreter_)(*context_);
     if (!context_->dStack.empty())
@@ -81,7 +104,7 @@ double CompiledDoubleModel::operator()(const double *arg,
 // IO //////////////////////////////////////////////////////////////////////////
 ostream & Latan::operator<<(std::ostream &out, CompiledDoubleModel &m)
 {
-    m.interpreter_->compile();
+    m.compile();
     out << *(m.interpreter_);
     
     return out;
diff --git a/lib/CompiledModel.hpp b/lib/CompiledModel.hpp
index 420ba6d..85c626e 100644
--- a/lib/CompiledModel.hpp
+++ b/lib/CompiledModel.hpp
@@ -48,8 +48,13 @@ public:
     friend std::ostream & operator<<(std::ostream &out,
                                      CompiledDoubleModel &f);
 private:
-    std::shared_ptr<MathInterpreter> interpreter_;
-    std::shared_ptr<RunContext>      context_;
+    // compile
+    void compile(void) const;
+private:
+    std::shared_ptr<MathInterpreter>           interpreter_;
+    std::shared_ptr<RunContext>                context_;
+    std::shared_ptr<std::vector<unsigned int>> varAddress_, parAddress_;
+    std::shared_ptr<bool>                      isCompiled_;
 };
 
 std::ostream & operator<<(std::ostream &out, CompiledDoubleModel &f);
diff --git a/lib/Math.cpp b/lib/Math.cpp
index ccaf267..99dcf06 100644
--- a/lib/Math.cpp
+++ b/lib/Math.cpp
@@ -90,63 +90,3 @@ DEF_STD_FUNC_2ARG(fmin)
 
 // Absolute value
 DEF_STD_FUNC_1ARG(fabs)
-
-#define ADD_FUNC(func) fTable[#func] = &STDMATH_NAMESPACE::func
-void STDMATH_NAMESPACE::addStdMathFunc(FunctionTable &fTable)
-{
-    // Trigonometric functions
-    ADD_FUNC(cos);
-    ADD_FUNC(sin);
-    ADD_FUNC(tan);
-    ADD_FUNC(acos);
-    ADD_FUNC(asin);
-    ADD_FUNC(atan);
-    ADD_FUNC(atan2);
-    
-    // Hyperbolic functions
-    ADD_FUNC(cosh);
-    ADD_FUNC(sinh);
-    ADD_FUNC(tanh);
-    ADD_FUNC(acosh);
-    ADD_FUNC(asinh);
-    ADD_FUNC(atanh);
-    
-    // Exponential and logarithmic functions
-    ADD_FUNC(exp);
-    ADD_FUNC(log);
-    ADD_FUNC(log10);
-    ADD_FUNC(exp2);
-    ADD_FUNC(expm1);
-    ADD_FUNC(log1p);
-    ADD_FUNC(log2);
-    
-    // Power functions
-    ADD_FUNC(pow);
-    ADD_FUNC(sqrt);
-    ADD_FUNC(cbrt);
-    ADD_FUNC(hypot);
-    
-    // Error and gamma functions
-    ADD_FUNC(erf);
-    ADD_FUNC(erfc);
-    ADD_FUNC(tgamma);
-    ADD_FUNC(lgamma);
-    
-    // Rounding and remainder functions
-    ADD_FUNC(ceil);
-    ADD_FUNC(floor);
-    ADD_FUNC(fmod);
-    ADD_FUNC(trunc);
-    ADD_FUNC(round);
-    ADD_FUNC(rint);
-    ADD_FUNC(nearbyint);
-    ADD_FUNC(remainder);
-    
-    // Minimum, maximum, difference functions
-    ADD_FUNC(fdim);
-    ADD_FUNC(fmax);
-    ADD_FUNC(fmin);
-    
-    // Absolute value
-    ADD_FUNC(fabs);
-}
diff --git a/lib/Math.hpp b/lib/Math.hpp
index 52d150b..8ceb763 100644
--- a/lib/Math.hpp
+++ b/lib/Math.hpp
@@ -95,9 +95,6 @@ DECL_STD_FUNC(fabs)
 
 namespace STDMATH_NAMESPACE
 {
-    // Add standard math functions to a table for the math compiler
-    void addStdMathFunc(FunctionTable &fTable);
-    
     // Constants
     const double pi = 3.1415926535897932384626433832795028841970;
 }
diff --git a/lib/MathInterpreter.cpp b/lib/MathInterpreter.cpp
index 5b4abfa..8dcdcf0 100644
--- a/lib/MathInterpreter.cpp
+++ b/lib/MathInterpreter.cpp
@@ -19,6 +19,7 @@
 
 #include <LatAnalyze/MathInterpreter.hpp>
 #include <LatAnalyze/includes.hpp>
+#include <LatAnalyze/Math.hpp>
 
 using namespace std;
 using namespace Latan;
@@ -41,12 +42,14 @@ ostream &Latan::operator<<(ostream& out, const Instruction& ins)
 Push::Push(const double val)
 : type_(ArgType::Constant)
 , val_(val)
+, address_(0)
 , name_("")
 {}
 
-Push::Push(const string &name)
+Push::Push(const unsigned int address, const string &name)
 : type_(ArgType::Variable)
 , val_(0.0)
+, address_(address)
 , name_(name)
 {}
 
@@ -61,7 +64,7 @@ void Push::operator()(RunContext &context) const
     {
         try
         {
-            context.dStack.push(context.vTable.at(name_));
+            context.dStack.push(context.vMem[address_]);
         }
         catch (out_of_range)
         {
@@ -81,13 +84,14 @@ void Push::print(ostream &out) const
     }
     else
     {
-        out << CODE_MOD << name_;
+        out << CODE_MOD << name_ << " @v" << address_;
     }
 }
 
 // Pop constructor /////////////////////////////////////////////////////////////
-Pop::Pop(const string &name)
-: name_(name)
+Pop::Pop(const unsigned int address, const string &name)
+: address_(address)
+, name_(name)
 {}
 
 // Pop execution ///////////////////////////////////////////////////////////////
@@ -95,7 +99,7 @@ void Pop::operator()(RunContext &context) const
 {
     if (!name_.empty())
     {
-        context.vTable[name_] = context.dStack.top();
+        context.vMem[address_] = context.dStack.top();
     }
     context.dStack.pop();
     context.insIndex++;
@@ -104,12 +108,13 @@ void Pop::operator()(RunContext &context) const
 // Pop print ///////////////////////////////////////////////////////////////////
 void Pop::print(ostream &out) const
 {
-    out << CODE_MOD << "pop" << CODE_MOD << name_;
+    out << CODE_MOD << "pop" << CODE_MOD << name_ << " @v" << address_;
 }
 
 // Store constructor ///////////////////////////////////////////////////////////
-Store::Store(const string &name)
-: name_(name)
+Store::Store(const unsigned int address, const string &name)
+: address_(address)
+, name_(name)
 {}
 
 // Store execution /////////////////////////////////////////////////////////////
@@ -117,7 +122,7 @@ void Store::operator()(RunContext &context) const
 {
     if (!name_.empty())
     {
-        context.vTable[name_] = context.dStack.top();
+        context.vMem[address_] = context.dStack.top();
     }
     context.insIndex++;
 }
@@ -125,12 +130,13 @@ void Store::operator()(RunContext &context) const
 // Store print /////////////////////////////////////////////////////////////////
 void Store::print(ostream &out) const
 {
-    out << CODE_MOD << "store" << CODE_MOD << name_;
+    out << CODE_MOD << "store" << CODE_MOD << name_ << " @v" << address_;
 }
 
 // Call constructor ////////////////////////////////////////////////////////////
-Call::Call(const string &name)
-: name_(name)
+Call::Call(const unsigned int address, const string &name)
+: address_(address)
+, name_(name)
 {}
 
 // Call execution //////////////////////////////////////////////////////////////
@@ -138,7 +144,7 @@ void Call::operator()(RunContext &context) const
 {
     try
     {
-        context.dStack.push((*context.fTable.at(name_))(context.dStack));
+        context.dStack.push((*context.fMem[address_])(context.dStack));
     }
     catch (out_of_range)
     {
@@ -150,7 +156,7 @@ void Call::operator()(RunContext &context) const
 // Call print //////////////////////////////////////////////////////////////////
 void Call::print(ostream &out) const
 {
-    out << CODE_MOD << "call" << CODE_MOD << name_;
+    out << CODE_MOD << "call" << CODE_MOD << name_ << " @f" << address_;
 }
 
 // Math operations /////////////////////////////////////////////////////////////
@@ -263,23 +269,40 @@ ostream &Latan::operator<<(ostream &out, const ExprNode &n)
     return out;
 }
 
-#define PUSH_INS(program, type, ...) \
+#define PUSH_INS(program, type, ...)\
 program.push_back(unique_ptr<type>(new type(__VA_ARGS__)))
+#define GET_ADDRESS(address, table, name)\
+try\
+{\
+    address = (table).at(name);\
+}\
+catch (out_of_range)\
+{\
+    address         = static_cast<unsigned int>((table).size());\
+    (table)[(name)] = address;\
+}\
 
 // VarNode compile /////////////////////////////////////////////////////////////
-void VarNode::compile(Program &program) const
+void VarNode::compile(Program &program, AddressTable &vTable,
+                      AddressTable &fTable __unused) const
 {
-    PUSH_INS(program, Push, getName());
+    unsigned int address;
+    
+    GET_ADDRESS(address, vTable, getName());
+    PUSH_INS(program, Push, address, getName());
+    
 }
 
 // CstNode compile /////////////////////////////////////////////////////////////
-void CstNode::compile(Program &program) const
+void CstNode::compile(Program &program, AddressTable &nextVAddress __unused,
+                      AddressTable &nextFAddress __unused) const
 {
     PUSH_INS(program, Push, strTo<double>(getName()));
 }
 
 // SemicolonNode compile ///////////////////////////////////////////////////////
-void SemicolonNode::compile(Program &program) const
+void SemicolonNode::compile(Program &program, AddressTable &vTable,
+                            AddressTable &fTable) const
 {
     auto &n = *this;
     
@@ -291,28 +314,31 @@ void SemicolonNode::compile(Program &program) const
         
         if (isAssign||isSemiColumn||isKeyword)
         {
-            n[i].compile(program);
+            n[i].compile(program, vTable, fTable);
         }
     }
 }
 
 // AssignNode compile //////////////////////////////////////////////////////////
-void AssignNode::compile(Program &program) const
+void AssignNode::compile(Program &program, AddressTable &vTable,
+                         AddressTable &fTable) const
 {
     auto &n = *this;
     
     if (isDerivedFrom<VarNode>(&n[0]))
     {
         bool hasSemicolonParent = isDerivedFrom<SemicolonNode>(getParent());
+        unsigned int address;
         
-        n[1].compile(program);
+        n[1].compile(program, vTable, fTable);
+        GET_ADDRESS(address, vTable, n[0].getName());
         if (hasSemicolonParent)
         {
-            PUSH_INS(program, Pop, n[0].getName());
+            PUSH_INS(program, Pop, address, n[0].getName());
         }
         else
         {
-            PUSH_INS(program, Store, n[0].getName());
+            PUSH_INS(program, Store, address, n[0].getName());
         }
     }
     else
@@ -326,13 +352,14 @@ void AssignNode::compile(Program &program) const
 #define ELIFNODE(name, nArg) else IFNODE(name, nArg)
 #define ELSE else
 
-void MathOpNode::compile(Program &program) const
+void MathOpNode::compile(Program &program, AddressTable &vTable,
+                         AddressTable &fTable) const
 {
     auto &n = *this;
     
     for (Index i = 0; i < n.getNArg(); ++i)
     {
-        n[i].compile(program);
+        n[i].compile(program, vTable, fTable);
     }
     IFNODE("-", 1)   PUSH_INS(program, Neg,);
     ELIFNODE("+", 2) PUSH_INS(program, Add,);
@@ -344,23 +371,27 @@ void MathOpNode::compile(Program &program) const
 }
 
 // FuncNode compile ////////////////////////////////////////////////////////////
-void FuncNode::compile(Program &program) const
+void FuncNode::compile(Program &program, AddressTable &vTable,
+                       AddressTable &fTable) const
 {
     auto &n = *this;
+    unsigned int address;
     
     for (Index i = 0; i < n.getNArg(); ++i)
     {
-        n[i].compile(program);
+        n[i].compile(program, vTable, fTable);
     }
-    PUSH_INS(program, Call, getName());
+    GET_ADDRESS(address, fTable, getName());
+    PUSH_INS(program, Call, address, getName());
 }
 
 // ReturnNode compile ////////////////////////////////////////////////////////////
-void ReturnNode::compile(Program &program) const
+void ReturnNode::compile(Program &program, AddressTable &vTable,
+                         AddressTable &fTable) const
 {
     auto &n = *this;
     
-    n[0].compile(program);
+    n[0].compile(program, vTable, fTable);
     program.push_back(nullptr);
 }
 
@@ -439,7 +470,57 @@ void MathInterpreter::parse(void)
 }
 
 // interpreter /////////////////////////////////////////////////////////////////
-void MathInterpreter::compile(void)
+#define ADD_FUNC(context, func)\
+try\
+{\
+(context).fMem[(context).fTable.at(#func)] = &STDMATH_NAMESPACE::func;\
+}\
+catch (out_of_range)\
+{}
+
+#define ADD_STDMATH_FUNCS(context)\
+ADD_FUNC(context, cos);\
+ADD_FUNC(context, sin);\
+ADD_FUNC(context, tan);\
+ADD_FUNC(context, acos);\
+ADD_FUNC(context, asin);\
+ADD_FUNC(context, atan);\
+ADD_FUNC(context, atan2);\
+ADD_FUNC(context, cosh);\
+ADD_FUNC(context, sinh);\
+ADD_FUNC(context, tanh);\
+ADD_FUNC(context, acosh);\
+ADD_FUNC(context, asinh);\
+ADD_FUNC(context, atanh);\
+ADD_FUNC(context, exp);\
+ADD_FUNC(context, log);\
+ADD_FUNC(context, log10);\
+ADD_FUNC(context, exp2);\
+ADD_FUNC(context, expm1);\
+ADD_FUNC(context, log1p);\
+ADD_FUNC(context, log2);\
+ADD_FUNC(context, pow);\
+ADD_FUNC(context, sqrt);\
+ADD_FUNC(context, cbrt);\
+ADD_FUNC(context, hypot);\
+ADD_FUNC(context, erf);\
+ADD_FUNC(context, erfc);\
+ADD_FUNC(context, tgamma);\
+ADD_FUNC(context, lgamma);\
+ADD_FUNC(context, ceil);\
+ADD_FUNC(context, floor);\
+ADD_FUNC(context, fmod);\
+ADD_FUNC(context, trunc);\
+ADD_FUNC(context, round);\
+ADD_FUNC(context, rint);\
+ADD_FUNC(context, nearbyint);\
+ADD_FUNC(context, remainder);\
+ADD_FUNC(context, fdim);\
+ADD_FUNC(context, fmax);\
+ADD_FUNC(context, fmin);\
+ADD_FUNC(context, fabs);
+
+void MathInterpreter::compile(RunContext &context)
 {
     bool gotReturn = false;
     
@@ -449,34 +530,43 @@ void MathInterpreter::compile(void)
         status_ |= Status::parsed;
         status_ -= status_ & Status::compiled;
     }
-    if (root_)
+    if (!(status_ & Status::compiled))
     {
-        root_->compile(program_);
-        for (unsigned int i = 0; i < program_.size(); ++i)
+        if (root_)
         {
-            if (!program_[i])
+            context.vTable.clear();
+            context.fTable.clear();
+            root_->compile(program_, context.vTable, context.fTable);
+            for (unsigned int i = 0; i < program_.size(); ++i)
             {
-                gotReturn = true;
-                program_.resize(i);
-                program_.shrink_to_fit();
-                break;
+                if (!program_[i])
+                {
+                    gotReturn = true;
+                    program_.resize(i);
+                    program_.shrink_to_fit();
+                    break;
+                }
             }
+            context.vMem.resize(context.vTable.size());
+            context.fMem.resize(context.fTable.size());
+            ADD_STDMATH_FUNCS(context);
         }
-        
+        if (!root_||!gotReturn)
+        {
+            LATAN_ERROR(Syntax, "expected 'return' in program '" + codeName_
+                        + "'");
+        }
+        status_ |= Status::compiled;
     }
-    if (!root_||!gotReturn)
-    {
-        LATAN_ERROR(Syntax, "expected 'return' in program '" + codeName_ + "'");
-    }
-    status_ |= Status::compiled;
 }
 
+
 // execution ///////////////////////////////////////////////////////////////////
 void MathInterpreter::operator()(RunContext &context)
 {
     if (!(status_ & Status::compiled))
     {
-        compile();
+        compile(context);
     }
     execute(context);
 }
diff --git a/lib/MathInterpreter.hpp b/lib/MathInterpreter.hpp
index 4a72397..973a6c1 100644
--- a/lib/MathInterpreter.hpp
+++ b/lib/MathInterpreter.hpp
@@ -36,15 +36,15 @@ BEGIN_NAMESPACE
 /******************************************************************************
  *                         Instruction classes                                *
  ******************************************************************************/
-typedef std::map<std::string, double>           VarTable;
-typedef std::map<std::string, DoubleFunction *> FunctionTable;
+typedef std::map<std::string, unsigned int> AddressTable;
 
 struct RunContext
 {
-    unsigned int       insIndex;
-    std::stack<double> dStack;
-    VarTable           vTable;
-    FunctionTable      fTable;
+    unsigned int                  insIndex;
+    std::stack<double>            dStack;
+    std::vector<double>           vMem;
+    std::vector<DoubleFunction *> fMem;
+    AddressTable                  vTable, fTable;
 };
 
 // Abstract base
@@ -77,15 +77,16 @@ private:
 public:
     //constructors
     explicit Push(const double val);
-    explicit Push(const std::string &name);
+    explicit Push(const unsigned int address, const std::string &name);
     // instruction execution
     virtual void operator()(RunContext &context) const;
 private:
     virtual void print(std::ostream& out) const;
 private:
-    ArgType     type_;
-    double      val_;
-    std::string name_;
+    ArgType      type_;
+    double       val_;
+    unsigned int address_;
+    std::string  name_;
 };
 
 // Pop
@@ -93,12 +94,13 @@ class Pop: public Instruction
 {
 public:
     //constructor
-    explicit Pop(const std::string &name);
+    explicit Pop(const unsigned int address, const std::string &name);
     // instruction execution
     virtual void operator()(RunContext &context) const;
 private:
     virtual void print(std::ostream& out) const;
 private:
+    unsigned int address_;
     std::string name_;
 };
 
@@ -107,12 +109,13 @@ class Store: public Instruction
 {
 public:
     //constructor
-    explicit Store(const std::string &name);
+    explicit Store(const unsigned int address, const std::string &name);
     // instruction execution
     virtual void operator()(RunContext &context) const;
 private:
     virtual void print(std::ostream& out) const;
 private:
+    unsigned int address_;
     std::string name_;
 };
 
@@ -121,12 +124,13 @@ class Call: public Instruction
 {
 public:
     //constructor
-    explicit Call(const std::string &name);
+    explicit Call(const unsigned int address, const std::string &name);
     // instruction execution
     virtual void operator()(RunContext &context) const;
 private:
     virtual void print(std::ostream& out) const;
 private:
+    unsigned int address_;
     std::string name_;
 };
 
@@ -167,7 +171,8 @@ public:
     // operator
     const ExprNode &operator[](const Index i) const;
     // compile
-    virtual void compile(Program &program) const = 0;
+    virtual void compile(Program &program, AddressTable &vTable,
+                         AddressTable &fTable) const = 0;
 private:
     std::string                             name_;
     std::vector<std::unique_ptr<ExprNode>>  arg_;
@@ -181,7 +186,8 @@ class name: public base\
 {\
 public:\
     using base::base;\
-    virtual void compile(Program &program) const;\
+    virtual void compile(Program &program, AddressTable &vTable,\
+                         AddressTable &fTable) const;\
 }
 
 DECL_NODE(ExprNode, VarNode);
@@ -195,7 +201,8 @@ class KeywordNode: public ExprNode
 {
 public:
     using ExprNode::ExprNode;
-    virtual void compile(Program &program) const = 0;
+    virtual void compile(Program &program, AddressTable &vTable,
+                         AddressTable &fTable) const = 0;
 };
 
 DECL_NODE(KeywordNode, ReturnNode);
@@ -245,7 +252,7 @@ public:
     // initialization
     void setCode(const std::string &code);
     // interpreter
-    void compile(void);
+    void compile(RunContext &context);
     // execution
     void operator()(RunContext &context);
     // IO