20. The apparatus as recited in claim 18 , at least one of the processor or the memory being further adapted for: removing the subset of the set of candidates and corresponding contexts from the set of candidates and corresponding contexts; and repeating the comparing, ranking, selecting, and adding steps for two or more iterations.
20. The apparatus as recited in claim 18 , at least one of the processor or the memory being further adapted for: removing the subset of the set of candidates and corresponding contexts from the set of candidates and corresponding contexts; and repeating the comparing, ranking, selecting, and adding steps for two or more iterations. 23. The apparatus as recited in claim 20 , at least one of the processor or the memory being further adapted for: discontinuing the iterations when a number of the selected subset of candidates is less than a predetermined threshold.