diff -r 59e005dcf163 -r 7550c816187a main_testing4/knight_test3.scala
--- a/main_testing4/knight_test3.scala	Thu Nov 02 23:34:53 2023 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,47 +0,0 @@
-import M4a._
-
-//type Pos = (Int, Int)    // a position on a chessboard 
-//type Path = List[Pos]    // a path...a list of positions
-
-def count_all_tours_urban(dim: Int) = {
-  for (i <- (0 until dim).toList; 
-       j <- (0 until dim).toList) yield count_tours(dim, List((i, j)))
-}
-
-def add_pair_urban(x: Pos)(y: Pos): Pos = 
-  (x._1 + y._1, x._2 + y._2)
-
-def is_legal_urban(dim: Int, path: Path)(x: Pos): Boolean = 
-  0 <= x._1 && 0 <= x._2 && x._1 < dim && x._2 < dim && !path.contains(x)
-
-def moves_urban(x: Pos): List[Pos] = 
-  List(( 1,  2),( 2,  1),( 2, -1),( 1, -2),
-       (-1, -2),(-2, -1),(-2,  1),(-1,  2)).map(add_pair_urban(x))
-
-def legal_moves_urban(dim: Int, path: Path, x: Pos): List[Pos] = 
-  moves_urban(x).filter(is_legal_urban(dim, path))
-
-def correct_urban(dim: Int)(p: Path): Boolean = p match {
-  case Nil => true
-  case x::Nil => true
-  case x::y::p => if (legal_moves_urban(dim, p, y).contains(x)) correct_urban(dim)(y::p) else false
-}
-
-
-assert(count_all_tours_urban(1) == List(1))
-assert(count_all_tours_urban(2) == List(0, 0, 0, 0))
-assert(count_all_tours_urban(3) == List(0, 0, 0, 0, 0, 0, 0, 0, 0))
-assert(count_all_tours_urban(4) == List(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
-//assert(count_all_tours_urban(5) == List(304, 0, 56, 0, 304, 0, 56, 0, 56, 0, 56, 0, 64, 0, 56, 0, 56, 0, 56, 0, 304, 0, 56, 0, 304))
-
-val ts00_urban = enum_tours(5, List((0, 0)))
-assert(ts00_urban.map(correct_urban(5)).forall(_ == true) == true)
-assert(ts00_urban.length == 304)  
-
-val ts01_urban = enum_tours(5, List((0, 1)))
-assert(ts01_urban.map(correct_urban(5)).forall(_ == true) == true)
-assert(ts01_urban.length == 0)  
-
-val ts02_urban = enum_tours(5, List((0, 2)))
-assert(ts02_urban.map(correct_urban(5)).forall(_ == true) == true)
-assert(ts02_urban.length == 56)