Chess Editor

Drag pieces to desired squares or edit Lambda. To remove, drag to trash.

Lambda

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

rank(1)
  rank(2)
  rank(3)
  rank(4)
  rank(5)
  rank(6)
  rank(7)
  rank(8)

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

empty(M,N) :-
  file(M) & rank(N) & ~occupied(M,N)

occupied(M,N) :- cell(M,N,R)

adjacent(cell(X1,Y),cell(X2,Y)) :- succ(X1,X2) & rank(Y)
adjacent(cell(X1,Y),cell(X2,Y)) :- succ(X2,X1) & rank(Y)
adjacent(cell(X,Y1),cell(X,Y2)) :- succ(Y1,Y2) & file(X)
adjacent(cell(X,Y1),cell(X,Y2)) :- succ(Y2,Y1) & file(X)
adjacent(cell(X1,Y1),cell(X2,Y2)) :- succ(X1,X2) & succ(Y1,Y2)
adjacent(cell(X1,Y1),cell(X2,Y2)) :- succ(X2,X1) & succ(Y1,Y2)
adjacent(cell(X1,Y1),cell(X2,Y2)) :- succ(X1,X2) & succ(Y2,Y1)
adjacent(cell(X1,Y1),cell(X2,Y2)) :- succ(X2,X1) & succ(Y2,Y1)

innerhtml(cell(M,N),"<img src='White_King.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,wk)
innerhtml(cell(M,N),"<img src='White_Queen.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,wq)
innerhtml(cell(M,N),"<img src='White_Bishop.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,wb)
innerhtml(cell(M,N),"<img src='White_Knight.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,wn)
innerhtml(cell(M,N),"<img src='White_Rook.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,wr)
innerhtml(cell(M,N),"<img src='White_Pawn.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,wp)
innerhtml(cell(M,N),"<img src='Black_King.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,bk)
innerhtml(cell(M,N),"<img src='Black_Queen.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,bq)
innerhtml(cell(M,N),"<img src='Black_Bishop.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,bb)
innerhtml(cell(M,N),"<img src='Black_Knight.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,bn)
innerhtml(cell(M,N),"<img src='Black_Rook.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,br)
innerhtml(cell(M,N),"<img src='Black_Pawn.png' height='50' draggable='true' ondragstart='drag(event)'/>") :- cell(M,N,bp)
innerhtml(cell(M,N)," ") :- empty(M,N)

style(cell(M,N),"cursor","pointer") :- cell(M,N,R)
style(cell(M,N),"cursor","text") :- empty(M,N)

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%%% Actions
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load :: false ==> true

drag(base(P),cell(X,Y)) :: empty(X,Y) ==> cell(X,Y,P)

drag(base(P),trash) :: false ==> true

drag(cell(U,V),trash) :: cell(U,V,P) ==> ~cell(U,V,P)

drag(cell(U,V),cell(X,Y)) :: cell(U,V,P) ==> ~cell(U,V,P) & cell(X,Y,P)
drag(cell(U,V),cell(X,Y)) :: cell(X,Y,P) ==> ~cell(X,Y,P)