Each output sequence comes with a probability indicating how likely is for the sequence to have been obtained by chance.

Initialize the output sequence of vertices to be empty.

Add v to the end of the output sequence.

Given a codeword, there are roughly 2 typical output sequences.

The task is to compute, given the parameters of the model, the probability of a particular output sequence.

The output sequence is the sequence of the which were not deleted, in the correct order and with no errors.

In this case the output sequence is called an l-sequence (for "long sequence").

A common performance measure is the least index of the least value in the output sequence.

For the special case of the Kronecker delta function, the output sequence is the impulse response:

One can see that the input being encoded is included in the output sequence too (look at the output 2).