diff --git a/src/collection.h b/src/collection.h
index de97a38..8dde98c 100644
--- a/src/collection.h
+++ b/src/collection.h
@@ -37,6 +37,7 @@ class String final : public TCollection, public Traits::Indexable, public Traits
 {
 public:
   using data_t = std::string;
+  using utype_t = data_t;
   
 private:
   data_t value;
diff --git a/src/help.cpp b/src/help.cpp
index a9a5ce8..853bdb5 100644
--- a/src/help.cpp
+++ b/src/help.cpp
@@ -104,9 +104,7 @@ void Help::init()
   addOperator("!", OpHelpEntry::unary(TYPE_LAMBDA, TYPE_UNKNOWN, "apply", Topic::FUNCTIONAL, "pop first value from stack and executes it as a lambda", "1 [2+] !", "3"));
   addOperator("!", OpHelpEntry::unary(TYPE_INT, TYPE_FLOAT, "factorial", Topic::NUMERICS, "computes factorial", "", ""));
   addOperator("=", OpHelpEntry::binary(TYPE_GENERIC, TYPE_GENERIC, TYPE_BOOL, "eq", Topic::LOGIC, "push true on stack if two topmost values are equal", "", ""));
-  
-  addOperator("^", OpHelpEntry::unary(TYPE_GENERIC, "peek", Topic::UTILITY, "prints stack topmost value", "", ""));
-  
+    
    addOperator("s", OpHelpEntry::unary(TYPE_GENERIC, TYPE_STRING, "string cast", Topic::TEXT, "convert the value to string", "", ""));
   
   addOperator("?", OpHelpEntry::binary(TYPE_BOOL, TYPE_LAMBDA, TYPE_UNKNOWN, "if", Topic::LOGIC, "executes lambda if boolean value is true", "", ""));
diff --git a/src/instruction.cpp b/src/instruction.cpp
index e0d2174..719233d 100644
--- a/src/instruction.cpp
+++ b/src/instruction.cpp
@@ -158,16 +158,6 @@ void Instruction::execute(VM *vm) const
       break;
     }
 
-    case OP_PEEK:
-    {
-      Value v = vm->peek();
-      
-      if (v.valid())
-        std::cout << v.svalue();
-      
-      break;
-    }
-      
     case OP_RAND:
     {
       if (vm->popOne(v1))
@@ -561,10 +551,7 @@ void Instruction::execute(VM *vm) const
       }
       break;
     }
-      
-    case OP_RAISE_STACK: { vm->raiseStack(); break; }
-    case OP_LOWER_STACK: { vm->lowerStack(); break; }
-      
+
     case OP_RAISE_STACKV:
     { 
       if (vm->popOne(v1) && v1.type == TYPE_INT)
diff --git a/src/main.cpp b/src/main.cpp
index 12a73c0..78a7002 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -96,9 +96,13 @@ int main (int argc, const char * argv[])
     else if (input == "info")
     {
       cout << "  arch: " << (sizeof(void*) == 4 ? "x86" : "x86-64") << endl;
-      cout << "  size of value        : " << sizeof(Value) << (sizeof(Value) == sizeof(value_data) + sizeof(Type) ? "  (packed)" : "") << endl;
-      cout << "  size of instruction  : " << sizeof(Instruction) << endl;
-      cout << "  size of opcode       : " << sizeof(Opcode) << endl;
+      cout << "  size of value         : " << sizeof(Value) << (sizeof(Value) == sizeof(value_data) + sizeof(Type) ? "  (packed)" : "") << endl;
+      cout << "  size of instruction   : " << sizeof(Instruction) << endl;
+      cout << "  size of opcode        : " << sizeof(Opcode) << endl;
+      cout << "  known types           : " << TypeTraits::traits().size() << endl;
+      cout << "  known operators       : " << Opcode::OPCODES_COUNT << endl;
+      cout << "  implemented operators : " << mc.vocabulary().size() << endl;
+
     }
     else
     {
diff --git a/src/microcode.cpp b/src/microcode.cpp
index d897e03..a4f7483 100644
--- a/src/microcode.cpp
+++ b/src/microcode.cpp
@@ -73,6 +73,14 @@ void registerTernary(MicroCode& mc, Topic topic, const std::string& name, const
   Help::addOperator(signature.opcode, signature.args, retn, topic, name, desc, examples);
 }
 
+template<typename T>
+void reverseCollection(VM* vm, const Value& v)
+{
+  const auto& data = v->as<T>->raw();
+  auto nv = T::utype_t(data.rbegin(), data.rend());
+  vm->push(new T(nv));
+}
+
 void registerFunctions(MicroCode& mc)
 {
   registerBinary(mc,
@@ -666,7 +674,24 @@ void registerStackFunctions(MicroCode& mc)
                 { OP_DROP, TRAIT_ANY_TYPE }, { },
                 [] (VM* vm, const Value& v) { }
                 );
-  
+
+  registerUnary(mc,
+                Topic::UTILITY, "peek", "prints stack topmost value",
+                {},
+                { OP_PEEK, TRAIT_ANY_TYPE }, { },
+                [](VM* vm, const Value& v) {
+                   /* TODO: optimize by avoiding popping and pushing */
+                   if (v.valid())
+                     std::cout << v.svalue();
+
+                   vm->push(v);
+
+                }
+  );
+
+  registerNullary(mc, Topic::UTILITY, "raise-stack", "switch to higher stack", {}, { OP_RAISE_STACK }, { }, [](VM* vm) { vm->raiseStack(); });
+  registerNullary(mc, Topic::UTILITY, "lower-stack", "switch to lower stack", {}, { OP_LOWER_STACK }, { }, [](VM* vm) { vm->lowerStack(); });
+
   //TODO: check return signature for rise and sink
   registerTernary(mc,
                   Topic::STACK, "rise", "cycle top three stack element left",
diff --git a/src/types/traits.cpp b/src/types/traits.cpp
index c02a81a..aa3814d 100644
--- a/src/types/traits.cpp
+++ b/src/types/traits.cpp
@@ -59,6 +59,7 @@ static const CollectionPrinter<Value> TuplePrinter = { "[[", "]]", " ", [] (cons
 
 static const auto unary_false = [](const Value&) { return false; };
 static const auto binary_false = [](const Value&, const Value&) { return false; };
+static const auto to_zero = [](const Value&) { return 0; };
 static const auto null_hasher = [](const Value&) { return 0UL; };
 static const auto default_collector = [](size_t hint) { return std::make_pair(TYPE_NONE, nullptr); };
 
@@ -71,6 +72,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       [] (const Value& v1, const Value& v2) { return v2.type == TYPE_INT && v2.data.i == v1.data.i; },
       [] (const Value& v) { return std::hash<integral_t>()(v.integral()); },
       unary_false,
+      [](const Value& v) { return v.integral(); },
       default_collector,
     }
   },
@@ -83,7 +85,8 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       },
       [] (const Value& v1, const Value& v2) { return v2.type == TYPE_FLOAT && v2.data.f == v1.data.f; },
       [] (const Value& v) { return std::hash<real_t>()(v.real()); },
-      unary_false
+      unary_false,
+      [](const Value& v) { return (int)v.real(); } 
     }
   },
   { TYPE_BOOL,
@@ -112,6 +115,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       [] (const Value& v1, const Value& v2) { return v2.type == TYPE_STRING && v2.string()->raw() == v1.string()->raw(); },
       [] (const Value& v) { return std::hash<std::string>()(v.string()->raw()); },
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_STRING, new String()); }
     }
   },
@@ -156,6 +160,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       binary_false,
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_ARRAY, new Array()); }
     }
   },
@@ -166,6 +171,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       [] (const Value& v1, const Value& v2) { return v2.type == TYPE_LIST && v2.list()->raw() == v1.list()->raw(); },
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_LIST, new List()); }
     }
   },
@@ -176,6 +182,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       binary_false,
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_ARRAY, new Array()); }
     }
   },
@@ -186,6 +193,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       binary_false,
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_SET, new Set()); }
     }
   },
@@ -195,6 +203,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       [] (const Value& v1, const Value& v2) { return v2.type == TYPE_STACK && v2.list()->raw() == v1.list()->raw(); },
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_LIST, new List()); }
     }
   },
@@ -204,6 +213,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       [] (const Value& v1, const Value& v2) { return v2.type == TYPE_QUEUE && v2.list()->raw() == v1.list()->raw(); },
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_LIST, new List()); }
     }
   },
@@ -221,6 +231,7 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
       binary_false,
       null_hasher,
       unary_false,
+      to_zero,
       [] (size_t hint) { return std::make_pair(TYPE_ARRAY, new Array()); }
     }
   },
@@ -355,6 +366,9 @@ const std::unordered_map<Type, TypeTraits::TypeSpec, enum_hash> TypeTraits::spec
             case OP_RECUR: return "[#]";
             case OP_RECURV: return "{#}";
             case OP_WHILE: return "<>";
+
+            case OP_RAISE_STACK: return "R";
+            case OP_LOWER_STACK: return "L";
          }
 
          assert(false);
diff --git a/src/types/traits.h b/src/types/traits.h
index 775e9d5..0128604 100644
--- a/src/types/traits.h
+++ b/src/types/traits.h
@@ -106,6 +106,7 @@ class TypeTraits
     std::function<size_t(const Value&)> hasher;
     
     std::function<bool(const Value&)> to_bool = [] (const Value& ) { return false; };
+    std::function<int(const Value&)> to_int = [](const Value&) { return 0; };
     
     std::function<std::pair<Type, Traits::Appendable*>(size_t)> to_collector = [] (size_t) { return std::make_pair(TYPE_NONE, nullptr); };