Let This can be viewed as a specific obligatory weighted context-dependent rewrite rule where the left and right contexts are not restricted (Kaplan and Kay, 1994;Mohri and Sproat, 1996).
the transduction corresponding to the class Í c an be viewed as the application of the following obligatory weighted rewrite rule: The direction of application of the rule, left-to-right or right-to-left, can be chosen depending on the task 2 .