We have multiple Gaussian variables, which could be the locations of 2-d points. Suppose the 2-d points are measured independently.
If we connect the adjacent points, then we will get a structure (graph). Suppose we have a model to compute whether the structure is stable or not.
How can we use the information about stable structure to correct the given measurements? We can anticipate that some positions of the 2-d points may cause an unstable structure. Hence, we can prune these positions and get a better estimate.