·Flat
 lexical structure
 ·Cross-word triphone
 modeling
 ·Multiplexing
 at word beginning
 ·Replication
 at word end
 ·Single-phone
 words: combination of both
 ·LM score applied upon
 transition into word
 ·Trigram
 language model
 ·However,
 only single best history maintained
 ·Beam-based
 pruning
 ·Long-tailed
 distribution of active HMMs/frame