1. A method comprising: generating, via a processor, 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 the input and a second finite-state machine representing the concatenated mapping, a third markup-language expression; and outputting the third markup-language expression.