diff --git a/src/parse.h b/src/parse.h
index fbefa80..c1c4f67 100644
--- a/src/parse.h
+++ b/src/parse.h
@@ -340,7 +340,7 @@ static bool get_float(const string& entry, program& prog, string& remaining_entr
             number* num = (number*)prog.allocate_back((unsigned int)sizeof(number), cmd_number, MPFR_128BITS_STORING_LENGTH, &significand);
             num->init(significand);
 
-            int mpfr_ret = mpfr_strtofr(&num->_value.mpfr, entry.c_str(), &endptr, 0, MPFR_DEF_RND);
+            int mpfr_ret = mpfr_strtofr(num->_value.mpfr, entry.c_str(), &endptr, 0, MPFR_DEF_RND);
             if (endptr != entry.c_str())
             {
                 ret = true;
diff --git a/src/rpn-binary.h b/src/rpn-binary.h
index 2207460..ac12d94 100644
--- a/src/rpn-binary.h
+++ b/src/rpn-binary.h
@@ -26,7 +26,7 @@ void rtob()
     number* left = (number*)_stack->pop_back();
 
     binary bin;
-    bin.set(mpfr_get_sj(&left->_value.mpfr, s_mpfr_rnd));
+    bin.set(mpfr_get_sj(left->_value.mpfr, s_mpfr_rnd));
     _stack->push_back(&bin, bin.size(), cmd_binary);
 }
 
diff --git a/src/rpn-branch.h b/src/rpn-branch.h
index 2ceea7a..12d616d 100644
--- a/src/rpn-branch.h
+++ b/src/rpn-branch.h
@@ -6,7 +6,7 @@ int rpn_if(branch& myobj)
     MIN_ARGUMENTS_RET(1, -1);
     ARG_MUST_BE_OF_TYPE_RET(0, cmd_number, -1);
 
-    if (mpfr_cmp_si(&((number*)_stack->get_obj(0))->_value.mpfr, 0UL) != 0)
+    if (mpfr_cmp_si(((number*)_stack->get_obj(0))->_value.mpfr, 0UL) != 0)
         myobj.arg1 = 1;
     else
         myobj.arg1 = 0;
@@ -55,27 +55,15 @@ int rpn_start(branch& myobj)
 
     // farg1 = first value of start command
     // farg2 = last value of start command
-cout<<__FUNCTION__<<": copy_and_push_back(farg2)"<<endl;
     stack::copy_and_push_back(*_stack, 0, _branch_stack);
-cout<<"[(number*)_stack->get_obj(0)="; ((number*)_stack->get_obj(0))->show(cout);cout<<"]\n";
-cout<<"(number*)_stack->get_obj(0)="<<(void*)_stack->get_obj(0)<<"=";
-dump8((unsigned char*)_stack->get_obj(0), 0, 40);
     myobj.farg2 = (number*)_branch_stack.get_obj(0);
     myobj.farg2->init(_branch_stack.get_blob(0));
     _stack->pop_back();
-cout<<"myobj.farg2="<<(void*)myobj.farg2<<"=";
-dump8((unsigned char*)myobj.farg2, 0, 40);
-cout<<"[-> arg2="; myobj.farg2->show(cout);cout<<"]\n";
 
-cout<<__FUNCTION__<<": copy_and_push_back(farg1)"<<endl;
     stack::copy_and_push_back(*_stack, 0, _branch_stack);
-cout<<"[(number*)_stack->get_obj(0)="; ((number*)_stack->get_obj(0))->show(cout);cout<<"]\n";
-cout<<"[_branch_stack.size()="<<_branch_stack.size()<<"]\n";
     myobj.farg1 = (number*)_branch_stack.get_obj(0);
     myobj.farg1->init(_branch_stack.get_blob(0));
     _stack->pop_back();
-cout<<"[myobj.farg2->_value.mpfr._mpfr_d="; myobj.farg2->_value.mpfr._mpfr_d;cout<<"]\n";
-cout<<"[-> arg2="; myobj.farg2->show(cout);cout<<"]\n";
     return -1;
 }
 
@@ -118,7 +106,7 @@ int rpn_next(branch& myobj)
     }
 
     // increment then test
-    mpfr_add_si(&myobj.farg1->_value.mpfr, &myobj.farg1->_value.mpfr, 1UL, MPFR_DEF_RND);
+    mpfr_add_si(myobj.farg1->_value.mpfr, myobj.farg1->_value.mpfr, 1UL, MPFR_DEF_RND);
 
     // for command: increment symbol too
     if (start_or_for->arg1 != -1)
diff --git a/src/rpn-logs.h b/src/rpn-logs.h
index 31bc7e6..49ce87f 100644
--- a/src/rpn-logs.h
+++ b/src/rpn-logs.h
@@ -1,7 +1,7 @@
 void rpn_e(void)
 {
     number num;
-    CHECK_MPFR(mpfr_const_euler(&num._value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_const_euler(num._value.mpfr, s_mpfr_rnd));
     _stack->push_back(&num, num.size(), cmd_number);
     ((number*)_stack->back())->ensure_significand();
 }
@@ -12,7 +12,7 @@ void rpn_log()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_log10(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_log10(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_alog()
@@ -21,7 +21,7 @@ void rpn_alog()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_exp10(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_exp10(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_ln()
@@ -30,7 +30,7 @@ void rpn_ln()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_log(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_log(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_exp()
@@ -39,7 +39,7 @@ void rpn_exp()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_exp(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_exp(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_sinh()
@@ -48,7 +48,7 @@ void rpn_sinh()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_sinh(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_sinh(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_asinh()
@@ -57,7 +57,7 @@ void rpn_asinh()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_asinh(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_asinh(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_cosh()
@@ -66,7 +66,7 @@ void rpn_cosh()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_cosh(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_cosh(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_acosh()
@@ -75,7 +75,7 @@ void rpn_acosh()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_cosh(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_cosh(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_tanh()
@@ -84,7 +84,7 @@ void rpn_tanh()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_tanh(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_tanh(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_atanh()
@@ -93,5 +93,5 @@ void rpn_atanh()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_atanh(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_atanh(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
diff --git a/src/rpn-real.h b/src/rpn-real.h
index 5955f83..38b667e 100644
--- a/src/rpn-real.h
+++ b/src/rpn-real.h
@@ -9,7 +9,7 @@ void plus()
 
         number* right = (number*)_stack->pop_back();
         number* left = (number*)_stack->back();
-        CHECK_MPFR(mpfr_add(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
+        CHECK_MPFR(mpfr_add(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
     }
     // binary
     else if (IS_ARG_TYPE(0, cmd_binary))
@@ -35,7 +35,7 @@ void minus()
 
         number* right = (number*)_stack->pop_back();
         number* left = (number*)_stack->back();
-        CHECK_MPFR(mpfr_sub(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
+        CHECK_MPFR(mpfr_sub(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
     }
     // binary
     else if (IS_ARG_TYPE(0, cmd_binary))
@@ -59,7 +59,7 @@ void mul()
 
         number* right = (number*)_stack->pop_back();
         number* left = (number*)_stack->back();
-        CHECK_MPFR(mpfr_mul(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
+        CHECK_MPFR(mpfr_mul(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
     }
     // binary
     else if (IS_ARG_TYPE(0, cmd_binary))
@@ -85,7 +85,7 @@ void div()
 
         number* right = (number*)_stack->pop_back();
         number* left = (number*)_stack->back();
-        CHECK_MPFR(mpfr_div(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
+        CHECK_MPFR(mpfr_div(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
     }
     // binary
     else if (IS_ARG_TYPE(0, cmd_binary))
@@ -114,7 +114,7 @@ void neg()
     if (IS_ARG_TYPE(0, cmd_number))
     {
         number* left = (number*)_stack->back();
-        CHECK_MPFR(mpfr_neg(&left->_value.mpfr, &left->_value.mpfr, s_mpfr_rnd));
+        CHECK_MPFR(mpfr_neg(left->_value.mpfr, left->_value.mpfr, s_mpfr_rnd));
     }
     // binary
     else if (IS_ARG_TYPE(0, cmd_binary))
@@ -129,7 +129,7 @@ void inv()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     number* left = (number*)_stack->back();
-    CHECK_MPFR(mpfr_si_div(&left->_value.mpfr, 1L, &left->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_si_div(left->_value.mpfr, 1L, left->_value.mpfr, s_mpfr_rnd));
 }
 
 void purcent()
@@ -141,8 +141,8 @@ void purcent()
     number* right = (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    CHECK_MPFR(mpfr_mul(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
-    CHECK_MPFR(mpfr_div_si(&left->_value.mpfr, &left->_value.mpfr, 100L, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_mul(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_div_si(left->_value.mpfr, left->_value.mpfr, 100L, s_mpfr_rnd));
 }
 
 void purcentCH()
@@ -154,8 +154,8 @@ void purcentCH()
     number* right = (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    CHECK_MPFR(mpfr_mul_si(&right->_value.mpfr, &right->_value.mpfr, 100L, s_mpfr_rnd));
-    CHECK_MPFR(mpfr_div(&left->_value.mpfr, &right->_value.mpfr, &left->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_mul_si(right->_value.mpfr, right->_value.mpfr, 100L, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_div(left->_value.mpfr, right->_value.mpfr, left->_value.mpfr, s_mpfr_rnd));
 }
 
 void power()
@@ -166,7 +166,7 @@ void power()
 
     number* right = (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
-    CHECK_MPFR(mpfr_pow(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_pow(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
 }
 
 void squareroot()
@@ -175,7 +175,7 @@ void squareroot()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     number* left = (number*)_stack->back();
-    CHECK_MPFR(mpfr_sqrt(&left->_value.mpfr, &left->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_sqrt(left->_value.mpfr, left->_value.mpfr, s_mpfr_rnd));
 }
 
 void square()
@@ -184,7 +184,7 @@ void square()
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     number* left = (number*)_stack->back();
-    CHECK_MPFR(mpfr_sqr(&left->_value.mpfr, &left->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_sqr(left->_value.mpfr, left->_value.mpfr, s_mpfr_rnd));
 }
 
 void modulo()
@@ -196,5 +196,5 @@ void modulo()
     number* right = (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    CHECK_MPFR(mpfr_fmod(&left->_value.mpfr, &left->_value.mpfr, &right->_value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_fmod(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
 }
diff --git a/src/rpn-stack.h b/src/rpn-stack.h
index 42c40bf..0fc0719 100644
--- a/src/rpn-stack.h
+++ b/src/rpn-stack.h
@@ -1,17 +1,15 @@
-stack _stack_manip;
-
 //
 void swap(void)
 {
     MIN_ARGUMENTS(2);
-    
-    stack::copy_and_push_back(*_stack, _stack->size()-1, _stack_manip);
-    stack::copy_and_push_back(*_stack, _stack->size()-2, _stack_manip);
+    stack::copy_and_push_back(*_stack, _stack->size()-1, _branch_stack);
+    stack::copy_and_push_back(*_stack, _stack->size()-2, _branch_stack);
     (void)_stack->pop_back();
     (void)_stack->pop_back();
-    stack::copy_and_push_back(_stack_manip, 0, *_stack);
-    stack::copy_and_push_back(_stack_manip, 1, *_stack);
-    _stack_manip.erase();
+    stack::copy_and_push_back(_branch_stack, 0, *_stack);
+    stack::copy_and_push_back(_branch_stack, 1, *_stack);
+    (void)_branch_stack.pop_back();
+    (void)_branch_stack.pop_back();
 }
 
 void drop(void)
@@ -67,17 +65,18 @@ void rot(void)
 {
     MIN_ARGUMENTS(3);
 
-    //TODO could be optimized
-    stack::copy_and_push_back(*_stack, _stack->size()-3, _stack_manip);
-    stack::copy_and_push_back(*_stack, _stack->size()-2, _stack_manip);
-    stack::copy_and_push_back(*_stack, _stack->size()-1, _stack_manip);
+    stack::copy_and_push_back(*_stack, _stack->size()-3, _branch_stack);
+    stack::copy_and_push_back(*_stack, _stack->size()-2, _branch_stack);
+    stack::copy_and_push_back(*_stack, _stack->size()-1, _branch_stack);
     (void)_stack->pop_back();
     (void)_stack->pop_back();
     (void)_stack->pop_back();
-    stack::copy_and_push_back(_stack_manip, 2, *_stack);
-    stack::copy_and_push_back(_stack_manip, 1, *_stack);
-    stack::copy_and_push_back(_stack_manip, 0, *_stack);
-    _stack_manip.erase();
+    stack::copy_and_push_back(_branch_stack, 2, *_stack);
+    stack::copy_and_push_back(_branch_stack, 1, *_stack);
+    stack::copy_and_push_back(_branch_stack, 0, *_stack);
+    (void)_branch_stack.pop_back();
+    (void)_branch_stack.pop_back();
+    (void)_branch_stack.pop_back();
 }
 
 void depth(void)
diff --git a/src/rpn-test.h b/src/rpn-test.h
index 4ef1d4a..8f62c92 100644
--- a/src/rpn-test.h
+++ b/src/rpn-test.h
@@ -7,10 +7,10 @@ void sup(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp(&left->_value.mpfr, &right->_value.mpfr) > 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp(left->_value.mpfr, right->_value.mpfr) > 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void sup_eq(void)
@@ -22,10 +22,10 @@ void sup_eq(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp(&left->_value.mpfr, &right->_value.mpfr) >= 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp(left->_value.mpfr, right->_value.mpfr) >= 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void inf(void)
@@ -37,10 +37,10 @@ void inf(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp(&left->_value.mpfr, &right->_value.mpfr) < 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp(left->_value.mpfr, right->_value.mpfr) < 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void inf_eq(void)
@@ -52,10 +52,10 @@ void inf_eq(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp(&left->_value.mpfr, &right->_value.mpfr) <= 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp(left->_value.mpfr, right->_value.mpfr) <= 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void diff(void)
@@ -67,10 +67,10 @@ void diff(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp(&left->_value.mpfr, &right->_value.mpfr) != 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp(left->_value.mpfr, right->_value.mpfr) != 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void eq(void)
@@ -82,10 +82,10 @@ void eq(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp(&left->_value.mpfr, &right->_value.mpfr) == 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp(left->_value.mpfr, right->_value.mpfr) == 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void test_and(void)
@@ -97,11 +97,11 @@ void test_and(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if ((mpfr_cmp_si(&left->_value.mpfr, 0) == 0)
-        && (mpfr_cmp_si(&right->_value.mpfr, 0) == 0))
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if ((mpfr_cmp_si(left->_value.mpfr, 0) == 0)
+        && (mpfr_cmp_si(right->_value.mpfr, 0) == 0))
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void test_or(void)
@@ -113,11 +113,11 @@ void test_or(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if ((mpfr_cmp_si(&left->_value.mpfr, 0) == 0)
-        || (mpfr_cmp_si(&right->_value.mpfr, 0) == 0))
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if ((mpfr_cmp_si(left->_value.mpfr, 0) == 0)
+        || (mpfr_cmp_si(right->_value.mpfr, 0) == 0))
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);
 }
 
 void test_xor(void)
@@ -129,19 +129,19 @@ void test_xor(void)
     number* right =  (number*)_stack->pop_back();
     number* left = (number*)_stack->back();
 
-    if (mpfr_cmp_si(&left->_value.mpfr, 0) == 0)
+    if (mpfr_cmp_si(left->_value.mpfr, 0) == 0)
     {
-        if (mpfr_cmp_si(&right->_value.mpfr, 0) != 0)
-            mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+        if (mpfr_cmp_si(right->_value.mpfr, 0) != 0)
+            mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
         else
-            mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);            
+            mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);            
     }
     else
     {
-        if (mpfr_cmp_si(&right->_value.mpfr, 0) == 0)
-            mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+        if (mpfr_cmp_si(right->_value.mpfr, 0) == 0)
+            mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
         else
-            mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);            
+            mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);            
     }
 }
 
@@ -151,10 +151,10 @@ void test_not(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     number* left = (number*)_stack->back();
-    if (mpfr_cmp_si(&left->_value.mpfr, 0) == 0)
-        mpfr_set_si(&left->_value.mpfr, 1, s_mpfr_rnd);
+    if (mpfr_cmp_si(left->_value.mpfr, 0) == 0)
+        mpfr_set_si(left->_value.mpfr, 1, s_mpfr_rnd);
     else
-        mpfr_set_si(&left->_value.mpfr, 0, s_mpfr_rnd);            
+        mpfr_set_si(left->_value.mpfr, 0, s_mpfr_rnd);            
 }
 
 void same(void)
diff --git a/src/rpn-trig.h b/src/rpn-trig.h
index 8ba911c..33c2d38 100644
--- a/src/rpn-trig.h
+++ b/src/rpn-trig.h
@@ -2,7 +2,7 @@
 void pi(void)
 {
     number num;
-    CHECK_MPFR(mpfr_const_pi(&num._value.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_const_pi(num._value.mpfr, s_mpfr_rnd));
     _stack->push_back(&num, num.size(), cmd_number);
     ((number*)_stack->back())->ensure_significand();
 }
@@ -14,9 +14,9 @@ void d2r(void)
 
     floating_t pi;
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_const_pi(&pi.mpfr, s_mpfr_rnd));
-    CHECK_MPFR(mpfr_mul(&left->mpfr, &left->mpfr, &pi.mpfr, s_mpfr_rnd));
-    CHECK_MPFR(mpfr_div_si(&left->mpfr, &left->mpfr, 180, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_const_pi(pi.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_mul(left->mpfr, left->mpfr, pi.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_div_si(left->mpfr, left->mpfr, 180, s_mpfr_rnd));
 }
 
 void r2d(void)
@@ -26,9 +26,9 @@ void r2d(void)
 
     floating_t pi;
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_const_pi(&pi.mpfr, s_mpfr_rnd));
-    CHECK_MPFR(mpfr_mul_si(&left->mpfr, &left->mpfr, 180, s_mpfr_rnd));
-    CHECK_MPFR(mpfr_div(&left->mpfr, &left->mpfr, &pi.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_const_pi(pi.mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_mul_si(left->mpfr, left->mpfr, 180, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_div(left->mpfr, left->mpfr, pi.mpfr, s_mpfr_rnd));
 }
 
 void rpn_sin(void)
@@ -37,7 +37,7 @@ void rpn_sin(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_sin(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_sin(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_asin(void)
@@ -46,7 +46,7 @@ void rpn_asin(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_asin(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_asin(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_cos(void)
@@ -55,7 +55,7 @@ void rpn_cos(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_cos(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_cos(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_acos(void)
@@ -64,7 +64,7 @@ void rpn_acos(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_acos(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_acos(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_tan(void)
@@ -73,7 +73,7 @@ void rpn_tan(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_tan(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_tan(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
 
 void rpn_atan(void)
@@ -82,5 +82,5 @@ void rpn_atan(void)
     ARG_MUST_BE_OF_TYPE(0, cmd_number);
 
     floating_t* left = &((number*)_stack->get_obj(0))->_value;
-    CHECK_MPFR(mpfr_atan(&left->mpfr, &left->mpfr, s_mpfr_rnd));
+    CHECK_MPFR(mpfr_atan(left->mpfr, left->mpfr, s_mpfr_rnd));
 }
diff --git a/src/rpn.cpp b/src/rpn.cpp
index 2e4b1d4..a16e9e8 100644
--- a/src/rpn.cpp
+++ b/src/rpn.cpp
@@ -106,52 +106,52 @@ typedef long long integer_t;
 // MPFR object
 struct floating_t
 {
-    __mpfr_struct mpfr;
+    mpfr_t mpfr;
 
     void init(void* significand)
     {
         mpfr_custom_init(significand, MPFR_128BITS_STORING_LENGTH);
-        mpfr_custom_init_set(&mpfr, MPFR_ZERO_KIND, 0, s_mpfr_prec, significand);
+        mpfr_custom_init_set(mpfr, MPFR_ZERO_KIND, 0, s_mpfr_prec, significand);
     }
 
     void set_significand(void* significand)
     {
-        mpfr._mpfr_d = (mp_limb_t*)significand;
+        mpfr->_mpfr_d = (mp_limb_t*)significand;
     }
 
     floating_t& operator=(const long int val)
     {
-        mpfr_set_si(&mpfr, val, s_mpfr_rnd);
+        mpfr_set_si(mpfr, val, s_mpfr_rnd);
     }
 
     floating_t& operator=(const unsigned long val)
     {
-        mpfr_set_ui(&mpfr, val, s_mpfr_rnd);
+        mpfr_set_ui(mpfr, val, s_mpfr_rnd);
     }
 
     floating_t& operator=(const integer_t val)
     {
-        mpfr_set_sj(&mpfr, val, s_mpfr_rnd);
+        mpfr_set_sj(mpfr, val, s_mpfr_rnd);
     }
 
     operator int()
     {
-        return (int)mpfr_get_si(&mpfr, s_mpfr_rnd);
+        return (int)mpfr_get_si(mpfr, s_mpfr_rnd);
     }
     
     void ensure_significand()
     {
-        //mpfr._mpfr_d = (mp_limb_t*)significand;
+        //mpfr->_mpfr_d = (mp_limb_t*)significand;
     }
 
     bool operator>(const floating_t right)
     {
-        return mpfr_cmp(&mpfr, &right.mpfr) > 0;
+        return mpfr_cmp(mpfr, right.mpfr) > 0;
     }
 
     bool operator<(const floating_t right)
     {
-        return mpfr_cmp(&mpfr, &right.mpfr) < 0;
+        return mpfr_cmp(mpfr, right.mpfr) < 0;
     }
 };
 
@@ -190,14 +190,14 @@ struct number : public object
     void copy(number& op)
     {
         _value = op._value;
-        memcpy(_value.mpfr._mpfr_d, op._value.mpfr._mpfr_d, MPFR_128BITS_STORING_LENGTH);
+        memcpy(_value.mpfr->_mpfr_d, op._value.mpfr->_mpfr_d, MPFR_128BITS_STORING_LENGTH);
     }
 
     //
     void set(const floating_t& value)
     {
         _type = cmd_number;
-        _value.mpfr._mpfr_d = value.mpfr._mpfr_d;
+        _value.mpfr->_mpfr_d = value.mpfr->_mpfr_d;
     }
 
     void set(long value)
@@ -221,7 +221,7 @@ struct number : public object
 
     void ensure_significand()
     {
-        //_value.mpfr._mpfr_d = (mp_limb_t*)_value.significand;
+        //_value.mpfr->_mpfr_d = (mp_limb_t*)_value.significand;
     }
 
     //
@@ -382,8 +382,8 @@ struct branch : public object
         arg1 = -1;
         arg2 = -1;
         arg3 = -1;
-        farg1 = 0L;
-        farg2 = 0L;
+        farg1 = NULL;
+        farg2 = NULL;
         arg_bool = 0;
         if (value != NULL)
         {
@@ -401,7 +401,7 @@ struct branch : public object
     branch_fn_t _fn;
     // args used by cmd_branch cmds
     int arg1, arg2, arg3;
-    floating_t farg1, farg2;
+    number *farg1, *farg2;
     bool arg_bool;
     unsigned int _len;
     char _value[0];
@@ -415,7 +415,7 @@ void object::show(ostream& stream)
     {
     case cmd_number:
         //(void)mpfr_printf(s_mpfr_printf_format.c_str(), &((number*)this)->_value.mpfr);
-        (void)mpfr_sprintf(buffer, s_mpfr_printf_format.c_str(), &((number*)this)->_value.mpfr);
+        (void)mpfr_sprintf(buffer, s_mpfr_printf_format.c_str(), ((number*)this)->_value.mpfr);
         stream<<buffer;
         break;
     case cmd_binary:
@@ -576,6 +576,7 @@ public:
                 i++;
             }
         }
+
         return ret;
     }
 
@@ -833,6 +834,7 @@ private:
     string _err_context;
 
     stack* _stack;
+    stack _branch_stack;
 
     heap* _global_heap;
     heap _local_heap;
@@ -884,7 +886,6 @@ private:
     #define ARG_MUST_BE_OF_TYPE(num, type) do { if (_stack->get_type(num) != (type)) { ERR_CONTEXT(ret_bad_operand_type); return; } } while(0)
     #define ARG_MUST_BE_OF_TYPE_RET(num, type, ret) do { if (_stack->get_type(num) != (type)) { ERR_CONTEXT(ret_bad_operand_type); return (ret); } } while(0)
     #define IS_ARG_TYPE(num, type) (_stack->get_type(num) == (type))
-    //TODO
     #define CHECK_MPFR(op) do { (void)(op); } while(0)
 
     // keywords implementation
diff --git a/src/stack.h b/src/stack.h
index a7f9d6d..0cac9b2 100644
--- a/src/stack.h
+++ b/src/stack.h
@@ -61,7 +61,7 @@ public:
         }
     }
 
-    // index_from is counted from back, last entry is 0
+    //
     static void copy_and_push_back(stack& from, unsigned int index_from, stack& to)
     {
         // copy a whole stack entry (with blob) and push it back to another stack
@@ -83,6 +83,7 @@ public:
             _base = (char*)realloc(_base, _total_size);
             _current = _base + offset;
         }
+
         if (_current_blob + blob_size > _blob + _total_blob_size)
         {
             unsigned long offset = _current_blob - _blob;
@@ -105,7 +106,6 @@ public:
         _vtype.push_back(type);
         _count++;
 
-//cout<<__FUNCTION__<<": -> stack size is "<<_count<<endl;//lru
         return allocated;
     }
 
@@ -118,7 +118,7 @@ public:
             _current = _vpointer[_count - 1];
             _vlen.pop_back();
             _vpointer.pop_back();
-            
+
             _current_blob = _vpointer_blob[_count - 1];
             _vlen_blob.pop_back();
             _vpointer_blob.pop_back();