Stochastic Syntax-Directed Translation Schemata for Correction of Errors in Context-Free Languages

A formal method of correcting errors of changed, deleted, and inserted terminals in the strings of a context-free language is considered. Grammars generating strings containing these errors are first constructed from a known grammar for the language; these new grammars are then used to specify simple syntax-directed translation schemata which can parse both correct strings and strings with errors and simultaneously produce output strings in the original language. Stochastic aspects of productions and of errors are incorporated into the correction model to assign probabilities to translations produced.