diff -r 663c2a9108d1 -r 4de31fdc0d67 testing4/re_test1.scala
--- a/testing4/re_test1.scala	Sun Nov 01 01:21:31 2020 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,11 +0,0 @@
-import CW9c._
-
-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)
-