A machine translation system generates an output sentence one word at a time, where each new word is chosen based on the original input sentence and the words already generated. When translating a long, complex sentence, the system produces an output that starts accurately but then devolves into a repetitive, nonsensical phrase (e.g., '...the boy is going to the is going to the is going to the...'). What is the most likely flaw in the generation process that would cause this specific type of err