diff -r 16dbc95d7d77 -r 316f9c6cc2ff testing3/re1a_test.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing3/re1a_test.scala	Thu Nov 23 10:56:47 2017 +0000
@@ -0,0 +1,21 @@
+
+import scala.concurrent._
+import scala.concurrent.duration._
+import ExecutionContext.Implicits.global
+import scala.language.postfixOps 
+import scala.language.reflectiveCalls
+
+lazy val f = Future {
+  import CW8a._
+
+  assert(nullable(ZERO) == false)
+  assert(nullable(ONE) == true)
+  assert(nullable(CHAR('a')) == false)
+  assert(nullable(ZERO | ONE) == true)
+  assert(nullable(ZERO | CHAR('a')) == false)
+  assert(nullable(ONE ~  ONE) == true)
+  assert(nullable(ONE ~ CHAR('a')) == false)
+  assert(nullable(STAR(ZERO)) == true)
+}
+
+Await.result(f, 120 second)