## Practical considerations

In practice, computing the -construction using Algorithm  is only feasible for high-rate codes because the algorithm needs to maintain a list of coset leaders at each iteration.

Another problem with the -construction is that it is theoretically possible for bounding to be so severe as to halt the construction when, for example, does not return a vector for a particular code . Though we have not seen this with trellis state bounding (i.e., using the mapping ), we have seen indications that this can occur with . Of course, certain constraints will simply not correspond to any existing linear code, so this problem is inherent to code design.