diff --git a/regression/orig/test055.log b/regression/orig/test055.log
new file mode 100644
index 000000000..12decc137
--- /dev/null
+++ b/regression/orig/test055.log
@@ -0,0 +1,2 @@
+0
+3
diff --git a/regression/test055.expr b/regression/test055.expr
new file mode 100644
index 000000000..00b21a292
--- /dev/null
+++ b/regression/test055.expr
@@ -0,0 +1,8 @@
+fun len(l) {
+  case l of
+     _ : xs -> return len(xs) + 1
+    |{} -> return 0 
+  esac
+}
+write(len({}));
+write(len({1, 2, 3}))
\ No newline at end of file
diff --git a/regression/test055.input b/regression/test055.input
new file mode 100644
index 000000000..e69de29bb