Problem: Unmatched

It is always a good to look at the unmatched points. There are many
reasons for having unmatched points (spare cells, lockup latches, test pins,
and so on). Many of them are in the implementation. Unmatched points in the
reference design are usually compare points, which are unused and optimized
away by the synthesis.

If there is no valid reason for these points to be unmatched, they will cause a
failing verification. This is because these points will appear as "unmatched
inputs" of downstream logic cones, and will generate a failure if the value is
part of the function of the next compare point.

In many cases there can be unmatched points but the verification result might
still be SUCCEEDED.