Forcing Chain - a chain that has 2 or more implication streams that start from one node and end in another node where the outcomes of inferences merge from the 2 implication streams.

• 强制链：一个有2个或以上隐含串的链，它以两条隐含串结合起来达到从一个节点向另外一个节点相互推论前进的形式。