16. A computer-readable storage medium storing instructions which, when executed by a computing device, cause the computing device to perform a method comprising: generating, from an input lattice representing a first modality of an input, a first markup-language expression; generating, via a finite-state transducer, a concatenated mapping, wherein the finite state transducer: uses the input lattice and a first finite-state machine having associated markup-language semantics to relate the first markup-language expression to a second markup-language expression representing a second modality based on a level of coincidence between the first modality and the second modality, to yield a mapping; and concatenates input symbols of the mapping associated with the markup-language semantics, to yield the concatenated mapping; generating, using a second finite-state machine representing the concatenated mapping and the input, a third markup-language expression; and outputting the third markup-language expression.
17. The computer-readable storage medium of claim 16 , wherein generating the concatenated mapping further comprises using a finite-state device representing a regular grammar comprising markup language tags in a terminal of the regular grammar.