On this page I put scans of papers that I could not
find online, and that have appeared many years ago.

R. Dassen, H.J. Hoogeboom, N. van Vugt.

A Characterization of noniterated splicing with regular rules.
In: Where Mathematics, Computer Science and Biology Meet
(C. MartinVide, V. Mitrana, eds.),
Kluwer Academic Publishers, 319327, November 2000.
scan © Kluwer
The family S(LIN,REG) of languages obtained by (noniterated) splicing linear
languages using regular rules does not coincide with one of the Chomsky
families.
We give a characterization of this family, and show that we can replace the
regular rule set by a finite one.

A. Ehrenfeucht, H.J. Hoogeboom, G. Rozenberg, N. van Vugt.

Forbidding and Enforcing.
In: DNA Based Computers V (E. Winfree, D. Gifford, eds.),
DIMACS Series in
Discrete Mathematics and Theoretical Computer Science, v. 54, 195206,
2000.
scan © American Mathematical Society

J. Engelfriet, H.J. Hoogeboom, J.P. van Best.

Trips on Trees.
Acta Cybernetica 14 (1999) 5164.
Now at publisher: www.inf.uszeged.hu/actacybernetica !
see Pebbles
A "trip" is a triple (g; u; v) where g is, in general, a graph and u and v are nodes of that graph. The trip is from u to v on the graph g. For the special case that g is a tree (or even a string) we investigate ways of specifying and implementing sets of trips. The main result is that a regular set of trips, specified as a regular tree language, can be implemented by a treewalking automaton that uses marbles and one pebble.

H.J. Hoogeboom, G. Rozenberg.

Diamond properties of elementary net systems.
Fundamenta Informaticae XIV (1991) 287300.
scan © IOS Press
An elementary net system is the basic model of net theory. The state
space of an
elementary net system is formalized through the notion of the case graph, which
is an edgelabelled
graph with a distinguished initial node. The paper investigates syntactic, i.e.,
graph theoretic properties of case graphs of elementary net systems. In
particular it studies the structure of isomorpisms between case graphs.