## HOUSTON JOURNAL OF MATHEMATICS

### Archived Edition
Vol. 13, No. 1, 1987

*Editors*: H. Brezis (Paris), J. Hausen (Houston), J.A. Johnson (Houston), B. Jóhnson (Nashville), A. Lelek (Houston), J. Nagata (Osaka), J.W. Neuberger (Emory), B.H. Neumann (Australian National University), G.-C. Rota (MIT)

*Managing Editor*: G.G. Johnson (Houston)

Houston Journal of Mathematics

*Contents*

**D. D. Anderson, David F. Anderson
**

Multiplicatively Closed Subsets of Fields, pp.
1-11.

**D. D. Anderson, James A. Huckaba, Ira J. Papick
**

A Note on Stable Domains, pp.
13-17.

**Ben Fitzpatrick, Jr., Norma F. Lauer
**

Densely Homogeneous Spaces (I), pp.
19-25.

**L. Fuchs
**

A Generalization of Almost Maximality of Valuation Domains, pp.
27-35.

**R. J. Gardner
**

Corson Compacts and Radon Spaces, pp. 37-46.

**Dragan S. Jankovic, Paul E. Long
**

A Note on H-Closed Spaces, pp. 47-50.

**Hisao Kato
**

Generalized Homogeneity of Continua and a Question of J. J. Charatonik, pp.
51-63.

**Daniel Katz
**

Two Applications of Asymptotic and Essential Sequences, pp.
65-73.

**Mumtaz Ahmad Khan
**

q-Analogues of Certain Operational Formulae, pp. 75-82.

**Ronald J. Leach
**

Variational Formulas for Some Classes of Analytic Functions, pp.
83-99.

**H. A. Priestley
**

Distributive Lattices Whose Ideal Lattices Are Catalytic, pp.
101-117.

**C. R. Putnam
**

Singular Commuting Perturbations of Operators and Hyponormality, pp. 119-134.

**James Simmons
**

Cyclic-Purity: A Generalization of Purity for Modules, pp. 135-150.