--- a/progs/pow.scala	Sat Dec 29 10:30:27 2018 +0000
+++ b/progs/pow.scala	Tue Feb 12 21:23:00 2019 +0000
@@ -45,6 +45,8 @@
 
 val A = Set("a", "b", "c")
 pow(A, 3)
+pow(A, 3).size
 
 val B = Set("a", "b", "")
 pow(B, 4)
+pow(B, 4).size