diff --git a/alib2algo/src/arbology/exact/ExactPatternMatch.h b/alib2algo/src/arbology/exact/ExactPatternMatch.h
index e82877c4474c695d067b2a54e990d4c64f5bfef5..f69338bb8acfb4776883faa27f958642433b2e3a 100644
--- a/alib2algo/src/arbology/exact/ExactPatternMatch.h
+++ b/alib2algo/src/arbology/exact/ExactPatternMatch.h
@@ -194,7 +194,7 @@ template < class SymbolType >
 bool ExactPatternMatch::matchHelper ( const ext::tree < common::ranked_symbol < SymbolType > > & subject, const ext::tree < common::ranked_symbol < SymbolType > > & pattern, const common::ranked_symbol < SymbolType > & subtreeVariable, const ext::set < common::ranked_symbol < SymbolType > > & nonlinearVariables, const ext::tree < common::ranked_symbol < unsigned > > & repeats, ext::map < common::ranked_symbol < SymbolType >, unsigned > & variablesSetting ) {
 	if ( pattern.getData ( ) == subtreeVariable ) return true;
 
-	if ( nonlinearVariables.count ( pattern.getData ( ) ) ) {
+	if ( nonlinearVariables.contains ( pattern.getData ( ) ) ) {
 		auto setting = variablesSetting.find ( pattern.getData ( ) );
 
 		if ( setting != variablesSetting.end ( ) ) return repeats.getData ( ).getSymbol ( ) == setting->second;
diff --git a/alib2algo/src/tree/exact/BackwardOccurrenceTest.h b/alib2algo/src/tree/exact/BackwardOccurrenceTest.h
index e05be3f1aadc2dfe91920df8cfbc0dd393e17f58..5568c8e316774ca7c74d7cd9c2e407f944b7a3c5 100644
--- a/alib2algo/src/tree/exact/BackwardOccurrenceTest.h
+++ b/alib2algo/src/tree/exact/BackwardOccurrenceTest.h
@@ -42,7 +42,7 @@ ext::pair < int, int > BackwardOccurrenceTest::occurrence ( const PrefixRankedBa
 			 // match of symbol
 			offset = offset - 1;
 			j = j - 1;
-		} else if ( ( pattern.getContent ( )[j] == pattern.getVariablesBar ( ) ) && ( subject.getBars ( ).count ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
+		} else if ( ( pattern.getContent ( )[j] == pattern.getVariablesBar ( ) ) && ( subject.getBars ( ).contains ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
 			 // match of variable with subtree
 			offset = subjectSubtreeJumpTable[offset];
 			j = j - 2;
@@ -71,13 +71,13 @@ ext::pair < int, int > BackwardOccurrenceTest::occurrence ( const PrefixRankedBa
 			 // match of symbol
 			offset = offset - 1;
 			j = j - 1;
-		} else if ( ( pattern.getContent ( )[j] == pattern.getVariablesBar ( ) ) && ( subject.getBars ( ).count ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
+		} else if ( ( pattern.getContent ( )[j] == pattern.getVariablesBar ( ) ) && ( subject.getBars ( ).contains ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
 			 // else match of variable with subtree
 			offset = subjectSubtreeJumpTable[offset];
 			j = j - 2;
 
 			 // check nonlinear variable
-			if ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( )[ j + 1 ] ) ) {
+			if ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( )[ j + 1 ] ) ) {
 				auto setting = variablesSetting.find ( pattern.getContent ( )[ j + 1 ] );
 
 				if ( setting != variablesSetting.end ( ) && repeats.getContent ( )[ offset + 1 ].getSymbol ( ) != setting->second )
diff --git a/alib2algo/src/tree/exact/ForwardOccurrenceTest.h b/alib2algo/src/tree/exact/ForwardOccurrenceTest.h
index 896df8a0847657930db8c8f5b0ee5cb9fee903d7..09b4ab97cb37a9d25fa3d198e6134b9d256df753 100644
--- a/alib2algo/src/tree/exact/ForwardOccurrenceTest.h
+++ b/alib2algo/src/tree/exact/ForwardOccurrenceTest.h
@@ -49,7 +49,7 @@ size_t ForwardOccurrenceTest::occurrence ( const PrefixRankedBarTree < SymbolTyp
 			 // match of symbol
 			offset = offset + 1;
 			j = j + 1;
-		} else if ( ( pattern.getContent ( )[j] == pattern.getSubtreeWildcard ( ) ) && ( ! subject.getBars ( ).count ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
+		} else if ( ( pattern.getContent ( )[j] == pattern.getSubtreeWildcard ( ) ) && ( ! subject.getBars ( ).contains ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
 			 // match of variable with subtree
 			offset = subjectSubtreeJumpTable[offset];
 			j = j + 2;
@@ -76,9 +76,9 @@ size_t ForwardOccurrenceTest::occurrence ( const PrefixRankedBarTree < SymbolTyp
 			 // match of symbol
 			offset = offset + 1;
 			j = j + 1;
-		} else if ( ( pattern.getContent ( )[j] == pattern.getSubtreeWildcard ( ) || pattern.getNonlinearVariables ( ).count ( pattern.getContent ( )[j] ) ) && ( ! subject.getBars ( ).count ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
+		} else if ( ( pattern.getContent ( )[j] == pattern.getSubtreeWildcard ( ) || pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( )[j] ) ) && ( ! subject.getBars ( ).contains ( subject.getContent ( )[offset] ) ) ) { //the second part of the condition is needed to handle S |S
 			 // check nonlinear variable
-			if ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( )[ j ] ) ) {
+			if ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( )[ j ] ) ) {
 				auto setting = variablesSetting.find ( pattern.getContent ( )[ j ] );
 
 				if ( setting != variablesSetting.end ( ) && repeats.getContent ( )[ offset ].getSymbol ( ) != setting->second )
@@ -143,9 +143,9 @@ size_t ForwardOccurrenceTest::occurrence ( const PrefixRankedTree < SymbolType >
 		if ( subject.getContent ( )[offset] == pattern.getContent ( )[j] )
 			 // match of symbol
 			offset = offset + 1;
-		else if ( pattern.getContent ( )[j] == pattern.getSubtreeWildcard ( ) || pattern.getNonlinearVariables ( ).count ( pattern.getContent ( )[ j ] ) ) {
+		else if ( pattern.getContent ( )[j] == pattern.getSubtreeWildcard ( ) || pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( )[ j ] ) ) {
 			 // check nonlinear variable
-			if ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( )[ j ] ) ) {
+			if ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( )[ j ] ) ) {
 				auto setting = variablesSetting.find ( pattern.getContent ( )[ j ] );
 
 				if ( setting != variablesSetting.end ( ) && repeats.getContent ( )[ offset ].getSymbol ( ) != setting->second )
diff --git a/alib2algo/src/tree/properties/BorderArrayNaive.h b/alib2algo/src/tree/properties/BorderArrayNaive.h
index c3d123f823770ad0ef8153bccdbc7327f36df2ea..2fda47ed3844c92f64b2271edb55c19194ba86c4 100644
--- a/alib2algo/src/tree/properties/BorderArrayNaive.h
+++ b/alib2algo/src/tree/properties/BorderArrayNaive.h
@@ -86,8 +86,8 @@ bool BorderArrayNaive::matches ( const tree::PrefixRankedBarNonlinearPattern < S
 		if ( pattern.getContent ( )[i] == pattern.getContent ( )[offset] ) {
 			i++;
 			offset++;
-		} else if ( ( pattern.getContent ( )[i] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( ) [ i ] ) )
-			 || ( pattern.getContent ( )[offset] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( ) [ offset ] ) ) ) {
+		} else if ( ( pattern.getContent ( )[i] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( ) [ i ] ) )
+			 || ( pattern.getContent ( )[offset] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( ) [ offset ] ) ) ) {
 			i = subtreeJumpTable[i];
 			offset = subtreeJumpTable[offset];
 		} else {
@@ -122,8 +122,8 @@ bool BorderArrayNaive::matches ( const tree::PrefixRankedNonlinearPattern < Symb
 		if ( pattern.getContent ( )[i] == pattern.getContent ( )[offset] ) {
 			i++;
 			offset++;
-		} else if ( ( pattern.getContent ( )[i] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( ) [ i ] ) )
-			 || ( pattern.getContent ( )[offset] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).count ( pattern.getContent ( ) [ offset ] ) ) ) {
+		} else if ( ( pattern.getContent ( )[i] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( ) [ i ] ) )
+			 || ( pattern.getContent ( )[offset] == pattern.getSubtreeWildcard ( ) ) || ( pattern.getNonlinearVariables ( ).contains ( pattern.getContent ( ) [ offset ] ) ) ) {
 			i = subtreeJumpTable[i];
 			offset = subtreeJumpTable[offset];
 		} else {