diff --git a/alib2/src/regexp/Alternation.cpp b/alib2/src/regexp/Alternation.cpp
index 305830de34d5bca8eb6df95fb51ee35a2a778b23..b7de7ca6d7636882d9a680712280b9dc57ac4ab2 100644
--- a/alib2/src/regexp/Alternation.cpp
+++ b/alib2/src/regexp/Alternation.cpp
@@ -29,6 +29,7 @@ Alternation::Alternation(const Alternation& other) {
 
 Alternation::Alternation(Alternation&& other) noexcept : elements(std::move(other.elements)) {
 	other.elements.clear();
+	this->attachRegExp(NULL);
 }
 
 Alternation& Alternation::operator=(const Alternation& other) {
@@ -132,6 +133,8 @@ bool Alternation::testSymbol( const alphabet::Symbol & symbol ) const {
 }
 
 bool Alternation::attachRegExp(const RegExp * regexp ) {
+	if(this->parentRegExp == regexp) return true;
+	
 	this->parentRegExp = regexp;
 	for(const auto& child : this->elements)
 		if(!child->attachRegExp(regexp)) return false;
diff --git a/alib2/src/regexp/Concatenation.cpp b/alib2/src/regexp/Concatenation.cpp
index 38da1d7e7222642309022e0a4be6b4db7f1707d1..4faa19cd58f453e0cc35a8781d971e9125cc02ad 100644
--- a/alib2/src/regexp/Concatenation.cpp
+++ b/alib2/src/regexp/Concatenation.cpp
@@ -28,6 +28,7 @@ Concatenation::Concatenation(const Concatenation& other) {
 
 Concatenation::Concatenation(Concatenation&& other) noexcept : elements(std::move(other.elements)) {
 	other.elements.clear();
+	this->attachRegExp(NULL);
 }
 
 Concatenation& Concatenation::operator=(const Concatenation& other) {
@@ -139,6 +140,7 @@ bool Concatenation::testSymbol( const alphabet::Symbol & symbol ) const {
 }
 
 bool Concatenation::attachRegExp(const RegExp * regexp ) {
+	if(this->parentRegExp == regexp) return true;
 	this->parentRegExp = regexp;
 	for(const auto& child : this->elements)
 		if(!child->attachRegExp(regexp)) return false;
diff --git a/alib2/src/regexp/Iteration.cpp b/alib2/src/regexp/Iteration.cpp
index 622d606cf833ee247ff64cee9595c2c9f2e77988..51c364c6e2ee46acb8c8e201eca55cbdf3466b0b 100644
--- a/alib2/src/regexp/Iteration.cpp
+++ b/alib2/src/regexp/Iteration.cpp
@@ -10,7 +10,7 @@
 
 namespace regexp {
 
-Iteration::Iteration(RegExpElement&& element) : element( NULL ){
+Iteration::Iteration(RegExpElement&& element) : element( NULL ) {
 	this->setElement(std::move(element));
 }
 
@@ -25,6 +25,7 @@ Iteration::Iteration(const Iteration& other) : element(other.element->clone()) {
 
 Iteration::Iteration(Iteration&& other) noexcept : element(other.element) {
 	other.element = nullptr;
+	this->attachRegExp(NULL);
 }
 
 Iteration& Iteration::operator=(const Iteration& other) {
@@ -108,6 +109,7 @@ bool Iteration::testSymbol( const alphabet::Symbol & symbol ) const {
 }
 
 bool Iteration::attachRegExp(const RegExp * regexp ) {
+	if(this->parentRegExp == regexp) return true;
 	this->parentRegExp = regexp;
 	return this->element->attachRegExp(regexp);
 }
diff --git a/alib2/src/regexp/RegExpEmpty.cpp b/alib2/src/regexp/RegExpEmpty.cpp
index aac9838617725642cd61fc8acebd83feb11f9540..90fbf970acd07f3f0737efc243a5cf52a793ee9e 100644
--- a/alib2/src/regexp/RegExpEmpty.cpp
+++ b/alib2/src/regexp/RegExpEmpty.cpp
@@ -8,6 +8,14 @@
 #include "RegExpEmpty.h"
 
 namespace regexp {
+  
+RegExpEmpty::RegExpEmpty(const RegExpEmpty& other) {
+  
+}
+
+RegExpEmpty::RegExpEmpty(RegExpEmpty&& other) {
+  this->attachRegExp(NULL);
+}
 
 RegExpElement* RegExpEmpty::clone() const {
 	return new RegExpEmpty(*this);
@@ -47,6 +55,7 @@ bool RegExpEmpty::testSymbol( const alphabet::Symbol & ) const {
 }
 
 bool RegExpEmpty::attachRegExp(const RegExp * regexp ) {
+	if(this->parentRegExp == regexp) return true;
 	this->parentRegExp = regexp;
 	return true;
 }
diff --git a/alib2/src/regexp/RegExpEmpty.h b/alib2/src/regexp/RegExpEmpty.h
index 52ec086c15a849d2c47d4c3f7740073c609ba74c..1293b61c38c00d28d9be12de64adee496d866e03 100644
--- a/alib2/src/regexp/RegExpEmpty.h
+++ b/alib2/src/regexp/RegExpEmpty.h
@@ -40,6 +40,9 @@ protected:
 	virtual void computeMinimalAlphabet( std::set<alphabet::Symbol>& alphabet ) const;
 
 public:
+	RegExpEmpty(const RegExpEmpty& other);
+	RegExpEmpty(RegExpEmpty&& other);
+  
 	virtual bool operator<(const RegExpElement&) const;
 	virtual bool operator==(const RegExpElement&) const;
 	virtual bool operator>(const RegExpElement&) const;
diff --git a/alib2/src/regexp/RegExpEpsilon.cpp b/alib2/src/regexp/RegExpEpsilon.cpp
index eed1754a8c6a4dc61fb8ef55fa2a77eb462d4242..0984e2ec81e2f874a26ab7fb5c47784d6f0b7c8a 100644
--- a/alib2/src/regexp/RegExpEpsilon.cpp
+++ b/alib2/src/regexp/RegExpEpsilon.cpp
@@ -9,6 +9,14 @@
 
 namespace regexp {
   
+RegExpEpsilon::RegExpEpsilon(const RegExpEpsilon& other) {
+  
+}
+
+RegExpEpsilon::RegExpEpsilon(RegExpEpsilon&& other) {
+	this->attachRegExp(NULL);
+}
+  
 RegExpElement* RegExpEpsilon::clone() const {
 	return new RegExpEpsilon(*this);
 }
@@ -47,6 +55,7 @@ bool RegExpEpsilon::testSymbol( const alphabet::Symbol & ) const {
 }
 
 bool RegExpEpsilon::attachRegExp(const RegExp * regexp ) {
+	if(this->parentRegExp == regexp) return true;
 	this->parentRegExp = regexp;
 	return true;
 }
diff --git a/alib2/src/regexp/RegExpEpsilon.h b/alib2/src/regexp/RegExpEpsilon.h
index 585bab24b86e3c1de6ebb0e5275a95fc9fb157f4..56c2a76cc029e67b43ec85f1eb21113f72fe93b5 100644
--- a/alib2/src/regexp/RegExpEpsilon.h
+++ b/alib2/src/regexp/RegExpEpsilon.h
@@ -40,6 +40,9 @@ protected:
 	virtual void computeMinimalAlphabet( std::set<alphabet::Symbol>& alphabet ) const;
 
 public:
+  
+	RegExpEpsilon(const RegExpEpsilon& other);
+	RegExpEpsilon(RegExpEpsilon&& other);
 	
 	virtual bool operator<(const RegExpElement&) const;
 	virtual bool operator==(const RegExpElement&) const;
diff --git a/alib2/src/regexp/RegExpSymbol.cpp b/alib2/src/regexp/RegExpSymbol.cpp
index c26c82b1a857218fbd143a2b4e4e750b14bae3a0..118340a1013e3d487641da26d99cefd6fdb18f4f 100644
--- a/alib2/src/regexp/RegExpSymbol.cpp
+++ b/alib2/src/regexp/RegExpSymbol.cpp
@@ -8,6 +8,14 @@
 #include "RegExpSymbol.h"
 
 namespace regexp {
+  
+RegExpSymbol::RegExpSymbol(const RegExpSymbol& other) : alphabet::Symbol(other.symbol) {
+  
+}
+
+RegExpSymbol::RegExpSymbol(RegExpSymbol&& other) : alphabet::Symbol(std::move(other.symbol)) {
+	this->attachRegExp(NULL);
+}
 
 RegExpSymbol::RegExpSymbol(const std::string& symbol) :
 		alphabet::Symbol(symbol) {
@@ -72,7 +80,9 @@ bool RegExpSymbol::testSymbol( const alphabet::Symbol & symbol ) const {
 }
 
 bool RegExpSymbol::attachRegExp(const RegExp * regexp ) {
+	if(this->parentRegExp == regexp) return true;
 	this->parentRegExp = regexp;
+	if(regexp == NULL) return true;
 	return this->parentRegExp->getAlphabet().find(*this) != this->parentRegExp->getAlphabet().end();
 }
 
diff --git a/alib2/src/regexp/RegExpSymbol.h b/alib2/src/regexp/RegExpSymbol.h
index 653e84675a409e504b55a007e4f01b378068dc85..0fa85b0b198f8bb8d96f298f04e20b0592134e4d 100644
--- a/alib2/src/regexp/RegExpSymbol.h
+++ b/alib2/src/regexp/RegExpSymbol.h
@@ -44,6 +44,9 @@ public:
 	RegExpSymbol(const std::string& symbol);
 	RegExpSymbol(std::string&& symbol);
 	
+	RegExpSymbol(const RegExpSymbol& other);
+	RegExpSymbol(RegExpSymbol&& other);
+	
 	bool operator==(const alphabet::Symbol&) const;
 	friend bool operator==(const alphabet::Symbol&, const RegExpSymbol&);