12. The method of claim 10 , wherein the generating of the optimal alignment includes repeating the following steps until an alignment respecting the contiguity constraint is produced: applying a first automaton to produce an alignment between the target sentence and the source sentence; determining whether the alignment meets the contiguity constraint, and, where the alignment does not meet the contiguity constraint, identifying which of the at least one candidate terms for which the contiguity constraint is not met; and generating a second automaton to enforce the contiguity constraint for those candidate terms for which the contiguity constraint is not met.
10. The method of claim 1 , wherein the generating of the optimal alignment includes generating a first automaton based on the probabilistic model and applying the first automaton in combination with a second automaton which enforces the contiguity constraint.