--- a/progs/lecture4.scala	Tue Nov 12 10:47:27 2019 +0000
+++ b/progs/lecture4.scala	Tue Nov 19 00:40:27 2019 +0000
@@ -22,7 +22,6 @@
 length_string_list(List("1", "2", "3", "4"))
 length_int_list(List(1, 2, 3, 4))
 
-//-----
 def length[A](lst: List[A]): Int = lst match {
   case Nil => 0
   case x::xs => 1 + length(xs)