Double check also be possible. For example, in the position shown, after Black plays 1...d5, White plays 2.exd6e.p. quintuple check (the "moa" is a non-leaping knight which first takes a diagonal step, then an orthogonal one). After the "en passant" capture, five pieces check the black king: both moas, the rook, the grasshopper and the bishop. In xiangqi, the Chinese version of chess, triple check and even quadruple check is possible even without using fairy pieces, as in the following examples: Double check In chess, a double check is a check delivered by two pieces simultaneously. In chess notation, it is almost
Double beta decay or double beta decay are predicted to be very long; hence, quadruple beta decay is unlikely to be realized. The eight candidate nuclei for quadruple beta decay include Zr, Xe, and Nd capable of quadruple beta-minus decay, and Xe, Ba, Gd, and Dy capable of quadruple beta-plus decay or electron capture. In theory, quadruple beta decay may be experimentally observable in three of these nuclei, with the most promising candidate being Nd. Double beta decay In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa,