Richard F. Arens, 10 Years After
1. Brief academic bio.
2. Arens’s 
phyla, presaging monoidal categories.
3. Arens’s 
phyla in a categorical time-line.
4. Dualization (*) and double dualization (**) in Arens’s 
phyla.
5. Arens’s principal ‡-construction (Arens multiplication):
 ** is monoidal.
6. Questions of symmetry/commutativity for **, 
 and some answers, both positive ...
7. ... and, after some preparatory work on commutativity, ...
8. ... negative (Zalduendo, [1991]).
9. Questions, open problems, ...
10. ... and a parallel with Bohr compactification for Abelian groups.