diff -r 59e005dcf163 -r 7550c816187a main_testing4/knight_test4.scala
--- a/main_testing4/knight_test4.scala	Thu Nov 02 23:34:53 2023 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,6 +0,0 @@
-import M4a._
-
-val f_urban = (x:(Int, Int)) => if (x._1 > 3) Some(List(x)) else None
-
-assert(first(List((1,0),(2,0),(3,0),(4,0)), f_urban) == Some(List((4,0))))
-assert(first(List((1,0),(2,0),(3,0)), f_urban) == None)