We show that k-tree isomorphism can be decided in logarithmic
space by giving a logspace canonical labeling algorithm. This improves
over the previous StUL upper bound and matches the lower bound. As a
consequence, the isomorphism, the automorphism, as well as the
canonization problem for k-trees ... more >>>

We present a logspace algorithm for computing a canonical interval representation and a canonical labeling of interval graphs. As a consequence, the isomorphism and automorphism problems for interval graphs are solvable in logspace.