guage ID is not mandatory, but helps in cases in which a word is found in the vocabulary of both languages and is pronounced differently), compatible pronunciation dictionaries and unigram word probabilities for each of the languages.
4 we compose the following FSTs: (a) an FST for converting a sentence into a sequence of phonemes, (b) an FST that allows minor changes in the phoneme sequence, (c) an FST for decoding a sequence of phonemes into a sentence, the inverse of (a).