' Savitch et al. have done an excellent job, both in their selections and in their commentaries, of giving a solid introduction to a sparsely cultivated but already complex field. They have also done much to foster the dissemination and the comprehension of formal complexity results in liguistics and to encourage accuracy and lucidity in the formulation, presentation, and interpretation of such results.' A. Manaster-Ramer in Computational Linguistics, 14:4 (December 1988)