--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pre_marking3/postfix_test1.scala	Fri Jan 15 02:40:57 2021 +0000
@@ -0,0 +1,7 @@
+import CW9a._
+
+
+assert(syard(split("3 + 4 * ( 2 - 1 )")) == List("3", "4", "2", "1", "-", "*", "+"))
+assert(syard(split("( ( ( 3 ) ) + ( ( 4 + ( 5 ) ) ) )")) == List("3", "4", "5", "+", "+"))
+assert(syard(split("5 + 7 / 2")) == List("5", "7", "2", "/", "+"))
+assert(syard(split("5 * 7 / 2")) == List("5", "7", "*", "2", "/"))