--- a/pre_testing1/collatz_test.sh	Sat Nov 28 12:09:55 2020 +0000
+++ b/pre_testing1/collatz_test.sh	Sat Nov 28 15:37:30 2020 +0000
@@ -27,7 +27,7 @@
 # purity test
 
 function scala_vars {
-   (egrep '\bvar\b|\breturn\b|\.par\.|\.par |ListBuffer|mutable|util.control|new Array' c$out 2> /dev/null 1> /dev/null)
+   (egrep '\bvar\b|\breturn\b|\.par\.|\.par |ListBuffer|AtomicInteger|mutable|util.control|new Array' c$out 2> /dev/null 1> /dev/null)
 }