Notes

1) The predicate pp/1 is printing out the board after each move. How it does it?. Would it matter if the board elements were messed up (not in order)? Would it be possible to write a recursive predicate that does the same operation? Again, would the order of board elements matter?

2) The board of the game could have alternative representations. For example:

(a) A list with 49 ordered places, i.e.:
board([-, -, h, …, c, -, -]).

(b) Two arguments which denote the current positions of c and h and a list which is initially empty and the crossed-out positions are inserted as the game progresses, i.e. initially:
board((4,1,c), (4,7,h), []).

What would be the pros and cons of the above representations, considering code complexity for list manipulation, ordering of list items, time and space efficiency, or any other factor you may think of?

3) This game could have variations in scale:
• It could be played on a smaller or bigger board, for example, a 5x5 or an 11x11 board.
• There could be more than 2 players.
• It could be 3-dimensional.
What changes, if any, would you perform and to which predicates, in order to make the program work in each of the above cases?