Defines things in the absolute term: "which piece lies in the square LIA?"
Denotes the color of a piece
Denotes the profession of a piece
Returns the list of all possible locations that a piece can move to / step on.
Spits out all the possible opponent (downward)'s move that is played from the hop1zuo1 onto the board.
Spits out all the possible opponent (downward)'s move that is played by moving a piece on the board, not from the hop1zuo1.