a1 Department of Mathematics University of Alabama Tuscaloosa, AL 35487, USA
a2 Department of Mathematics University of Lancaster Lancaster LA1 4YL, England
Let Tn be the operator algebra of upper triangular n × n complex matrices. Three families of limit algebras of the form lim (Tnk) are classified up to isometric algebra isomorphism: (i) the limit algebras arising when the embeddings Tnk→Tnk+1, are alternately of standard and refinement type; (ii) limit algebras associated with refinement embeddings with a single column twist; (iii) limit algebras determined by certain homogeneous embeddings. The last family is related to certain fractal like subsets of the unit square.
(Received February 21 1991)