Transitions about talking about the two methods in details in the next slides

Gaps can also be caused by deletion

Here we consider the pattern matching problem as a token sequence generation problem. So, we take the token sequence t1 till tL from the test instance and calculate its probability according to the training data. In a typical bigram model, this generation prob is multiplication of bigram probs. Here, we use linear interpolation to smooth the bigram probs and introduce two terms….