7. A computer-readable storage medium having encoded thereon computer-executable instructions that when executed by a processor cause the processor to perform steps comprising: performing text normalization using a context free transducer and a grammar, wherein performing text normalization comprises generating a lattice of output textual strings of symbols for a single input textual string of symbols, determining scores for paths through the lattice based on costs stored in the grammar, selecting a path through the lattice based on the scores, and designating the output textual string along the selected path as the text normalization of the input textual string and wherein the grammar comprises a pair of translate tags that define a transition for a transducer network, wherein between the pair of translate tags are multiple pairs of in tags and multiple pairs of out tags, and wherein text symbols between each pair of out tags represent a text normalization for text symbols between each pair of in tags and wherein text symbols between each pair of in tags represent an inverse text normalization for text symbols between each pair of out tags; and performing inverse text normalization using a context free transducer and the grammar.
7. A computer-readable storage medium having encoded thereon computer-executable instructions that when executed by a processor cause the processor to perform steps comprising: performing text normalization using a context free transducer and a grammar, wherein performing text normalization comprises generating a lattice of output textual strings of symbols for a single input textual string of symbols, determining scores for paths through the lattice based on costs stored in the grammar, selecting a path through the lattice based on the scores, and designating the output textual string along the selected path as the text normalization of the input textual string and wherein the grammar comprises a pair of translate tags that define a transition for a transducer network, wherein between the pair of translate tags are multiple pairs of in tags and multiple pairs of out tags, and wherein text symbols between each pair of out tags represent a text normalization for text symbols between each pair of in tags and wherein text symbols between each pair of in tags represent an inverse text normalization for text symbols between each pair of out tags; and performing inverse text normalization using a context free transducer and the grammar. 9. The computer-readable storage medium of claim 7 wherein the grammar comprises a set of rules and wherein at least one rule references another rule in the set of rules.