1 

     2 

     2 //type Pos = (Int, Int)    // a position on a chessboard 

     3 //type Pos = (Int, Int)    // a position on a chessboard 

     3 //type Path = List[Pos]    // a path...a list of positions

     4 //type Path = List[Pos]    // a path...a list of positions

     4 

     5 

     5 def add_pair_urban(x: Pos)(y: Pos): Pos = 

     6 def add_pair_urban(x: Pos)(y: Pos): Pos = 

    21   case x::y::p => 

    22   case x::y::p => 

    22     if (legal_moves_urban(dim, p, y).contains(x)) correct_urban(dim)(y::p) else false

    23     if (legal_moves_urban(dim, p, y).contains(x)) correct_urban(dim)(y::p) else false

    23 }

    24 }

    24 

    25 

    25 

    26 

    28 

    29 

    29 val ts2_urban = first_tour(4, List((0, 0)))

    30 val ts2_urban = first_tour(4, List((0, 0)))

    30 assert(ts2_urban == None)  

    31 assert(ts2_urban == None)