... ofdominoes on the boundary of each active face (see the picture below): If there is a single domino, along edge e,wemoveittoe; if there are two dominoes, we remove them; if thereis no domino, ... Propp. Alternating-signmatrices and domino tilings. J. Algebraic Combin., 1:111–132, 219–234, 1992.[4] William Jockusch, James Propp, and Peter Shor. Random domino tilings and the arcticcircle ... if either ρe− ρiis evenor ρe≥ 3ρi− 1.dominoes on the northern-most W-E diagonal of Aρeare oriented southwards, therefore thenumber of dominoes oriented southward on the W-E diagonal...