diff -r a359976a6f3e -r 975d34506e88 marking4/re_test1.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/marking4/re_test1.scala	Fri Dec 14 14:41:54 2018 +0000
@@ -0,0 +1,10 @@
+
+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)
+