Xiangqi Opening Trap: Central Cannon Double Headed Snake Variation
The diagrams shown one the famous Xiangqi Opening Trap. Before reached to this position, the previous move for Red was P7+1 for double headed snake formation. Obviously, Red want to develop his horse in next move.
Therefore, Black replied with C2=3 (Diagram 1). In Black's plan, if Red H8+7, then Black can P3+1 and threaten Red horse directly.... and mostly can gain a crossed river pawn!