COMMUNICATIONS IN ALGEBRA
Volume 28, Number 2, 2000CONTENTS
Classifying Pointed Hopf Algebras of Dimension 16 . . . 541 S. Caenepeel, S. Ddscalescu, and S. Raianu
An Isomorphism Theorem for Ore Extension Hopf Algebras . . . 569 M. Beattie
Clifford-Type Algebras as Cleft Extensions for Some Pointed
Hopf A l g e b r a s . . . 585 F. Panaite and F. Van Oystaeyen
On the Depth of the Canonical Modules of Graded Rings
Associated to an I d e a l . . . 601 T. Cortadellas
Valuation Ideals of Order One in 2-Dimensional Regular Local
R i n g s . . . 613 S.Noh
Unitary Units in Modular Group Algebras of 2 - G r o u p s . . . 625 A. Bovdi and L. Erdei
Quasi-Hopf Algebra Actions and Smash Products . . . 631 D. Bulacu, F. Panaite, and F. Van Oystaeyen
Principal and Plenary Train A l g e b r a s . . . 653 J. C. Gutierrez Ferndndez
On the Module of Differentials of a Noncommutative Algebra
and Symmetric Biderivations of a Semiprime Algebra . . . 669 M. Hongan and H. Komatsu
Quadratic Transform of Complete Ideals in Regular Local Rings... 693 C. D 'Cruz
Geometric Quantities Associated to Differential O p e r a t o r s . . . 699 P. Mathonet
Multivalued Sheaf Constructions . . . 719 R. Lowen, A. Verschoren, and N. A. Soultan
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viii CONTENTS Free Koszul Homology and Regular Ideals in Non-noetherian
R i n g s . . . 737 J. Majadas
Nil Semigroups of Endomorphism Rings of Modules with Chain
Conditions . . . 747 R. N. Gupta and D. Khurana
Rings with Countably Many Direct S u m m a n d s . . . 757 G. F. Birkenmeier, J. Y. Kirn, andJ. K. Park
Study of Hopficity in Certain Classes of Rings . . . 771
K. Varadarajan
Gorenstein Rings and Inverse P o l y n o m i a l s . . . 785 S. Park
On von Neumann Regular R i n g s . . . 791 C. V. Hong, J. Y. Kirn, andN. K. Kirn
Endomorphism Rings of Modules of Generalized Inverse
P o l y n o m i a l s . . . 803
Z Liu
On the Quotient Between Length and M u l t i p l i c i t y . . . 815 N. Allsop and L. T. Hoa
Quantum Z-Algebras and Representations of Quantum Affine
A l g e b r a s . . . 829 N. Jing
Polynomials with Frobenius Galois Groups . . . 845 L. Cangelmi
On Multiquadratic Extensions of n-Hilbert Fields in
Characteristic 2 . . . 861 C. M. dos Santas
The Lie w-Engel Property in Group Rings . . . 867 G. T. Lee
One-Relator Quotients of Free Products of Cyclic G r o u p s . . . 883 M. Edjvet and A. Juhdsz
Construction de Corps de Decomposition Grace aux Facteurs de
Resolvantes . . . 903
L. Ducos
CONTENTS IX Loewy Matrix, Koszul Cone, and Applications . . . 925 J.Y.GuoandQ. Wu
Real Quadratic Division A l g e b r a s . . . 941 E. Dieterich
Some Finitely Presented Nilpotent-by-Abelian G r o u p s . . . 949 D. H. Kochloukova
On Generalized Fibonacci Groups with an Odd Number of
G e n e r a t o r s . . . 959 A. Szczepariski and A. Vesnin
A. Splitting Theorem for Groups Acting on Quasi-trees . . . 967 M. Batty
Prime Ideals of the Enveloping Algebra U ( s l s ) . . . 981 S. Catoiu
The Coradical Filtration of Uy(Q) at Roots of U n i t y . . . 1029 E. Mutter
On the Range of a Lie Derivation on a Banach Algebra . . . 1045 M. I. Berenguer and A. R. Villena
Groups Related to Fox S u b g r o u p s . . . 1051 T. Hurley and S. Sehgal
On Ideals Consisting Entirely of Zero Divisors . . . 1061 F. Azarpanah, 0. A. S. Karamzadeh, and A. R. Aliabad
Global Dimension of Rings of Functions . . . 1075 R. T. Finn and J. Martinez
Coherent Archimedean/-Rings . . . 1091 B. LavriC
