diff --git a/src/ext/plantuml/com/google/zxing/ResultPoint.java b/src/ext/plantuml/com/google/zxing/ResultPoint.java
index 3ea9eb671..30a7eac9c 100644
--- a/src/ext/plantuml/com/google/zxing/ResultPoint.java
+++ b/src/ext/plantuml/com/google/zxing/ResultPoint.java
@@ -63,8 +63,8 @@ public class ResultPoint {
   }
 
   /**
-   * <p>Orders an array of three ResultPoints in an order [A,B,C] such that AB < AC and
-   * BC < AC and the angle between BC and BA is less than 180 degrees.
+   * <p>Orders an array of three ResultPoints in an order [A,B,C] such that AB is less than AC
+   * and BC is less than AC and the angle between BC and BA is less than 180 degrees.
    */
   public static void orderBestPatterns(ResultPoint[] patterns) {
 
diff --git a/src/net/sourceforge/plantuml/ebnf/EbnfSingleExpression.java b/src/net/sourceforge/plantuml/ebnf/EbnfSingleExpression.java
index 7bf12422e..bb219ce03 100644
--- a/src/net/sourceforge/plantuml/ebnf/EbnfSingleExpression.java
+++ b/src/net/sourceforge/plantuml/ebnf/EbnfSingleExpression.java
@@ -59,6 +59,7 @@ public class EbnfSingleExpression {
 			} else if (isLetterOrDigit(ch)) {
 				final String litteral = readLitteral(it);
 				tokens.add(new Token(Symbol.LITTERAL, litteral));
+				continue;
 			} else if (ch == ',') {
 				tokens.add(new Token(Symbol.CONCATENATION, null));
 			} else if (ch == '|') {
@@ -125,9 +126,9 @@ public class EbnfSingleExpression {
 				engine.alternation();
 			else if (element.getSymbol() == Symbol.CONCATENATION)
 				engine.concatenation();
-			else if (element.getSymbol() == Symbol.OPTIONAL_CLOSE)
+			else if (element.getSymbol() == Symbol.OPTIONAL)
 				engine.optional();
-			else if (element.getSymbol() == Symbol.REPETITION_CLOSE)
+			else if (element.getSymbol() == Symbol.REPETITION)
 				engine.repetition();
 			else
 				throw new UnsupportedOperationException(element.toString());
diff --git a/src/net/sourceforge/plantuml/ebnf/ShuntingYard.java b/src/net/sourceforge/plantuml/ebnf/ShuntingYard.java
index 31d5b5d1b..a26e61d2e 100644
--- a/src/net/sourceforge/plantuml/ebnf/ShuntingYard.java
+++ b/src/net/sourceforge/plantuml/ebnf/ShuntingYard.java
@@ -65,21 +65,15 @@ public class ShuntingYard {
 				if (operatorStack.peekFirst().getSymbol() == Symbol.GROUPING_OPEN)
 					operatorStack.removeFirst();
 			} else if (token.getSymbol() == Symbol.OPTIONAL_OPEN) {
-				operatorStack.addFirst(token);
+				operatorStack.addFirst(new Token(Symbol.OPTIONAL, null));
 			} else if (token.getSymbol() == Symbol.OPTIONAL_CLOSE) {
-				while (operatorStack.peekFirst().getSymbol() != Symbol.OPTIONAL_OPEN)
-					ouputQueue.add(operatorStack.removeFirst());
-				if (operatorStack.peekFirst().getSymbol() == Symbol.OPTIONAL_OPEN)
-					operatorStack.removeFirst();
-				operatorStack.addFirst(token);
+				final Token first = operatorStack.removeFirst();
+				ouputQueue.add(first);
 			} else if (token.getSymbol() == Symbol.REPETITION_OPEN) {
-				operatorStack.addFirst(token);
+				operatorStack.addFirst(new Token(Symbol.REPETITION, null));
 			} else if (token.getSymbol() == Symbol.REPETITION_CLOSE) {
-				while (operatorStack.peekFirst().getSymbol() != Symbol.REPETITION_OPEN)
-					ouputQueue.add(operatorStack.removeFirst());
-				if (operatorStack.peekFirst().getSymbol() == Symbol.REPETITION_OPEN)
-					operatorStack.removeFirst();
-				operatorStack.addFirst(token);
+				final Token first = operatorStack.removeFirst();
+				ouputQueue.add(first);
 			} else {
 				throw new UnsupportedOperationException(token.toString());
 			}
diff --git a/src/net/sourceforge/plantuml/ebnf/Symbol.java b/src/net/sourceforge/plantuml/ebnf/Symbol.java
index 90af08d92..6723d953d 100644
--- a/src/net/sourceforge/plantuml/ebnf/Symbol.java
+++ b/src/net/sourceforge/plantuml/ebnf/Symbol.java
@@ -46,8 +46,10 @@ public enum Symbol {
 	ALTERNATION, // |
 	OPTIONAL_OPEN, // [
 	OPTIONAL_CLOSE, // ]
+	OPTIONAL,
 	REPETITION_OPEN, // {
 	REPETITION_CLOSE, // }
+	REPETITION, // 
 	GROUPING_OPEN, // (
 	GROUPING_CLOSE, // )
 	TERMINAL_STRING1, // " "