diff --git a/examples/regexp/oppa-4-13.xml b/examples/regexp/oppa-4-13.xml
new file mode 100644
index 0000000000000000000000000000000000000000..43c4bd61ba33fcefae862aafea728314c2c1464c
--- /dev/null
+++ b/examples/regexp/oppa-4-13.xml
@@ -0,0 +1,26 @@
+<regexp>
+<alternation>
+	<concatenation>
+		<symbol>0</symbol>
+		<symbol>1</symbol>
+		<symbol>0</symbol>
+	</concatenation>
+	<concatenation>
+		<symbol>1</symbol>
+		<symbol>0</symbol>
+		<symbol>1</symbol>
+	</concatenation>
+	<concatenation>
+		<iteration>
+			<symbol>0</symbol>
+		</iteration>
+		<symbol>1</symbol>
+	</concatenation>
+	<concatenation>
+		<iteration>
+			<symbol>1</symbol>
+		</iteration>
+		<symbol>0</symbol>
+	</concatenation>
+</alternation>
+</regexp>
diff --git a/examples/regexp/oppa-4-14.xml b/examples/regexp/oppa-4-14.xml
new file mode 100644
index 0000000000000000000000000000000000000000..e1abbba00a48ae5860146bbdf31e8fa6c6a87eaa
--- /dev/null
+++ b/examples/regexp/oppa-4-14.xml
@@ -0,0 +1,19 @@
+<regexp>
+<iteration>
+	<alternation>
+		<concatenation>
+			<symbol>0</symbol>
+			<iteration>
+				<symbol>1</symbol>
+			</iteration>
+			<symbol>0</symbol>
+		</concatenation>
+		<concatenation>
+			<symbol>1</symbol>
+			<iteration>
+				<symbol>0</symbol>
+			</iteration>
+		</concatenation>
+	</alternation>
+</iteration>
+</regexp>
diff --git a/examples/regexp/oppa-4-15.xml b/examples/regexp/oppa-4-15.xml
new file mode 100644
index 0000000000000000000000000000000000000000..4d730256773653476e2d50142247b27b3293a182
--- /dev/null
+++ b/examples/regexp/oppa-4-15.xml
@@ -0,0 +1,12 @@
+<regexp>
+<concatenation>
+	<symbol>1</symbol>
+	<iteration>
+		<symbol>0</symbol>
+	</iteration>
+	<iteration>
+		<symbol>1</symbol>
+	</iteration>
+	<symbol>0</symbol>
+</concatenation>
+</regexp>