(role white)

(init (cell a 1 b))
(init (cell a 2 b))
(init (cell a 3 b))
(init (cell a 4 b))
(init (cell a 5 b))
(init (cell a 6 b))
(init (cell a 7 b))
(init (cell a 8 b))

(init (cell b 1 b))
(init (cell b 2 b))
(init (cell b 3 b))
(init (cell b 4 b))
(init (cell b 5 b))
(init (cell b 6 b))
(init (cell b 7 b))
(init (cell b 8 b))

(init (cell c 1 b))
(init (cell c 2 b))
(init (cell c 3 b))
(init (cell c 4 b))
(init (cell c 5 b))
(init (cell c 6 b))
(init (cell c 7 b))
(init (cell c 8 b))

(init (cell d 1 b))
(init (cell d 2 b))
(init (cell d 3 b))
(init (cell d 4 b))
(init (cell d 5 b))
(init (cell d 6 b))
(init (cell d 7 b))
(init (cell d 8 b))

(init (cell e 1 b))
(init (cell e 2 b))
(init (cell e 3 b))
(init (cell e 4 b))
(init (cell e 5 b))
(init (cell e 6 b))
(init (cell e 7 b))
(init (cell e 8 b))

(init (cell f 1 b))
(init (cell f 2 b))
(init (cell f 3 b))
(init (cell f 4 b))
(init (cell f 5 b))
(init (cell f 6 b))
(init (cell f 7 b))
(init (cell f 8 b))

(init (cell g 1 b))
(init (cell g 2 b))
(init (cell g 3 b))
(init (cell g 4 b))
(init (cell g 5 b))
(init (cell g 6 b))
(init (cell g 7 b))
(init (cell g 8 b))

(init (cell h 1 b))
(init (cell h 2 b))
(init (cell h 3 b))
(init (cell h 4 b))
(init (cell h 5 b))
(init (cell h 6 b))
(init (cell h 7 b))
(init (cell h 8 b))
(init (points 0))
(init initial)

(<= (next (cell ?u ?v b))
    (true (cell ?u ?v b))
    (does white (place ?x ?y))
    (distinct ?u ?x))

(<= (next (cell ?u ?v b))
    (true (cell ?u ?v b))
    (does white (place ?x ?y))
    (distinct ?v ?y))

(<= (next (cell ?u ?v wn))
    (does white (place ?u ?v)))

(<= (next (cell ?u ?v wn))
    (true (cell ?u ?v wn)))

(<= (legal white (place ?u ?v))
    (true (cell ?u ?v b)))

(<= terminal
    (true (cell ?x ?y wn))
    (true (cell ?u ?v wn))
    (knight_move ?u ?v ?x ?y))

(<= (goal white ?p)
    (true (points ?p)))

(<= (next (points ?y))
    (true (points ?x))
    (not (true initial))
    (succ ?x ?y))

(<= (next (points 0))
    (true initial))

; Up two + over one in any direction
(<= (knight_move ?u ?v ?x ?y)
    (adjacent_two ?v ?y)
    (adjacent ?u ?x))

; Up one + over two in any direction
(<= (knight_move ?u ?v ?x ?y)
    (adjacent_two ?u ?x)
    (adjacent ?v ?y))

;;;  DIFFERENT CELLS
;;;  True iff ?x1 ?y1 is a different cell from ?x2 ?y2
(<= (adjacent ?x1 ?x2)
    (next_file ?x1 ?x2))

(<= (adjacent ?x1 ?x2)
    (next_file ?x2 ?x1))

(<= (adjacent ?y1 ?y2)
    (next_rank ?y1 ?y2))

(<= (adjacent ?y1 ?y2)
    (next_rank ?y2 ?y1))

(<= (adjacent_two ?a ?b)
    (adjacent ?a ?mid)
    (adjacent ?mid ?b)
    (distinct ?a ?b))

(<= (clear_column ?u ?v ?y)
    (next_rank ?v ?y)
    (coordinate ?u))

(<= (clear_column ?u ?v ?y)
    (next_rank ?v ?w)
    (true (cell ?u ?w b))
    (clear_column ?u ?w ?y))

(<= (clear_row ?u ?x ?v)
    (next_file ?u ?x)
    (coordinate ?v))

(<= (clear_row ?u ?x ?v)
    (next_file ?u ?w)
    (true (cell ?w ?v b))
    (clear_row ?w ?x ?v))

(<= (different_cells ?x1 ?y1 ?x2 ?y2)
    (coordinate ?x1)
    (coordinate ?x2)
    (coordinate ?y1)
    (coordinate ?y2)
    (distinct ?x1 ?x2))

(<= (different_cells ?x1 ?y1 ?x2 ?y2)
    (coordinate ?x1)
    (coordinate ?x2)
    (coordinate ?y1)
    (coordinate ?y2)
    (distinct ?y1 ?y2))

; BOARD TOPOLOGY
(next_rank 1 2)
(next_rank 2 3)
(next_rank 3 4)
(next_rank 4 5)
(next_rank 5 6)
(next_rank 6 7)
(next_rank 7 8)

(next_file a b)
(next_file b c)
(next_file c d)
(next_file d e)
(next_file e f)
(next_file f g)
(next_file g h)

; BOARD COORDINATES
(coordinate 1)
(coordinate 2)
(coordinate 3)
(coordinate 4)
(coordinate 5)
(coordinate 6)
(coordinate 7)
(coordinate 8)
(coordinate a)
(coordinate b)
(coordinate c)
(coordinate d)
(coordinate e)
(coordinate f)
(coordinate g)
(coordinate h)

(succ 0 1)
(succ 1 2)
(succ 2 3)
(succ 3 4)
(succ 4 5)
(succ 5 6)
(succ 6 7)
(succ 7 8)
(succ 8 9)
(succ 9 10)
(succ 10 12)
(succ 12 14)
(succ 14 16)
(succ 16 18)
(succ 18 20)
(succ 20 22)
(succ 22 24)
(succ 24 26)
(succ 26 28)
(succ 28 30)
(succ 30 35)
(succ 35 40)
(succ 40 45)
(succ 45 50)
(succ 50 55)
(succ 55 60)
(succ 60 65)
(succ 65 70)
(succ 70 75)
(succ 75 80)
(succ 80 90)
(succ 90 100)

; These rules are strictly unnecessary, but suggest a helpful hint.
(square a 1 black)
(square a 3 black)
(square a 5 black)
(square a 7 black)
(square b 2 black)
(square b 4 black)
(square b 6 black)
(square b 8 black)
(square c 1 black)
(square c 3 black)
(square c 5 black)
(square c 7 black)
(square d 2 black)
(square d 4 black)
(square d 6 black)
(square d 8 black)
(square e 1 black)
(square e 3 black)
(square e 5 black)
(square e 7 black)
(square f 2 black)
(square f 4 black)
(square f 6 black)
(square f 8 black)
(square g 1 black)
(square g 3 black)
(square g 5 black)
(square g 7 black)
(square h 2 black)
(square h 4 black)
(square h 6 black)
(square h 8 black)

(square h 1 white)
(square h 3 white)
(square h 5 white)
(square h 7 white)
(square g 2 white)
(square g 4 white)
(square g 6 white)
(square g 8 white)
(square f 1 white)
(square f 3 white)
(square f 5 white)
(square f 7 white)
(square e 2 white)
(square e 4 white)
(square e 6 white)
(square e 8 white)
(square d 1 white)
(square d 3 white)
(square d 5 white)
(square d 7 white)
(square c 2 white)
(square c 4 white)
(square c 6 white)
(square c 8 white)
(square b 1 white)
(square b 3 white)
(square b 5 white)
(square b 7 white)
(square a 2 white)
(square a 4 white)
(square a 6 white)
(square a 8 white)