diff -r 80102fba0a93 -r 0ab369f53ac1 marking3/knight1_test3a.scala
--- a/marking3/knight1_test3a.scala	Sun Dec 09 01:36:49 2018 +0000
+++ b/marking3/knight1_test3a.scala	Mon Dec 10 02:23:30 2018 +0000
@@ -1,32 +1,12 @@
 
-type Pos = (Int, Int)    // a position on a chessboard 
-type Path = List[Pos]    // a path...a list of positions
+//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))