SMALL FOOTSTEPS IN A GIANT SHADOW
Rodica CETERCHI
Faculty of Mathematics and Computer Science
University of Bucharest
Email: rceterchi@funinf.cs.unibuc.ro,rceterchi@gmail.com
If we were to asign “Moisil numbers” to people in the following manner: people who knew him
directly (students, collaborators) to receive Moisil number one, and people who knew directly one
of the above to receive Moisil number two (and so on), then, in this hierarchy I would receive a
Moisil number two. The people with Moisil number one, who influenced my existence as a
mathematician and my work are: professors Solomon Marcus, Dragos Vaida, Sergiu Rudeanu,
Virgil E. Cazanescu, George Georgescu, Afrodita Iorgulescu, Alexandru Mateescu, Gheorghe
Paun, Cristian Calude, Ioan Tomescu, and many more. It was through their presence and
personality that, during my journey described below, I always felt Moisil as a friendly giant
shadow.
I did not know the great professor directly, apart from a short visit he paid to my Special
Mathematics class in the “I.L. Caragiale” high-school of Bucharest, visit which, unfortunately,
left me without recollections, since I was probably absent at that time.
I entered the Faculty of Mathematics in 1972, because of an intricate play of circumstances and
contradictory plans for the future (I was planning to become a film critic, while, at the same time,
attending the Special Mathematics class, and participating in school contests such as the Maths
olympics, but also the Literature olympics, and many others, with good results in all directions). I
graduated in 1976, and, after the Master (called specialization at that time) in 1977, I had a 9,83
final mark, which qualified me for research and University teaching, except that the rules had
changed, and a “production period” of at least 3 years was mandatory. I spent 4 years in
I.P.G.G.H. (Institute for Geological and Geophysical Prospecting); we were several
mathematicians there, and there were digital data and a modern computer to process them, and,
above all, our bosses had love of Mathematics and a hope that Mathematics could help
geophysical prediction by elaborating models. So we had weekly seminars held by Ciprian Foias
and Silviu Guiasu, the latter my former Master thesis advisor on the prediction of second-order
stochastic processes, and a specialist in Information theory, for which he aroused my interest.
At the suggestion of Professor Marcus I moved in 1981 to the Systems Studies Division of the
University of Bucharest, still quite big and interdisciplinary at that time, but which (I do not
recollect the year) was split in two, and I ended in the System Studies Group affiliated to the
Faculty of Mathematics. There, an interdisciplinary seminar survived, and I had the chance to
participate in the last period of a 4 years interdisciplinary and international contract GPID (Goals
Processes and Indicators of Development) with the United Nations University (UNU), which
brought me in contact with a wealth of new people and new ideas. It was a wonderful, even if
brief, opportunity, to meet and work with people such as Carlos Mallmann (from the Bariloche
Foundation), and Anthony Judge (from Brussels), to be exposed to a great variety of disciplines
and ideas which constantly enriched and reshaped my mindscape. This period culminated for me
with a UNU scholarship to attend the 1st Course on the Development Problematique held at
Fundacion Bariloche, Argentina. After that, direct contacts dissappeared completely, and, only
due to the relentless enthusiasm and decisive action by Prof. Marcus, we pursued such ventures
further with two more contracts with UNU: PDP (People, Development, Problematique) and
EAHD (Economic Aspects of Human Development).
Eventually, for political reasons, the group was dissolved, Mihai Botez was exiled to Tulcea, and
the rest of us were assigned to CCUB(from which Moisil had departed a long time ago, but in
which survived small islands of interests and research directions initiated by him).
This first part of my career was divided between interdisciplinary research and “pure’ math
research. The first paper I wrote and published, was in 1976, while still a student, under the
guidance of Prof. Marcus, and was of an interdisciplinary nature.
Next came the “Big Jump”: I passed from maths to Computer Science in 1989. I did not
understand much of CS in the introductory course attended in my second year of undergraduate
studies, so in the 3rd year I chose Mathematics instead of CS specialization. My self-excuse was
my reasoning that with a good Math background I could always switch to CS later, while the
reverse move seemed less feasible.
Beside Prof. Solomon Marcus, who encouraged this leap, there were other people who made the
leap possible: Prof. Dragos Vaida and Alexandru Mateescu . They both showed me that CS is
approachable by an algebraic set of mind, and Prof. Virgil Cazanescu did the same thing some
years later. In 1989 I entered the PhD programme in CS, and finished my thesis in September
1991 under the guidance of Prof. S. Marcus.
In 1991 I had my first PC, and, in a sense, this was my first “close encounter” with computers –
apart from the Sinclair Spectrum I had at home (and on which my children learned the alphabet
by typing code) and the remote connection with an unknown entity in ’74, when code written in
Fortran IV on special sheets was transformed into packages of punched cards tied together,
several such packages left the Faculty in a suitcase, went to Stefan Furtuna, then, after a week or
so, the suitcase came back with long sheets of papers, somebody divided them among us, and left
us with the task of deciphering and hunting mistakes…
With a PC in hands I had both the tool for editing my PhD thesis, and the tool for stepping into
the world of “applied” CS (i.e. in the world of programs). Because, at the same time, I formally
started my university career, by becoming an Assistant in the CS department of the Faculty in
Spring ’91, sustaining my thesis in September ’91, and being assigned my first course in CS (fall
’91) on Data Structures by Prof. Tomescu, the Dept. Head.
A very busy period started, in which, besides a heavy teaching load, I pursued my interests in
both Theoretical CS and applied CS, having to learn algorithms, data structures, programming
languages, computability and complexity, formal languages, etc. I also entered the field of
algebraic structures for many-valued logics, quite accidentally, being asked by Prof. Vaida to
replace him at an optional course for students of the 4th year, the person who literally placed my
first papers on MV algebras in my arms, to be read. When I asked him to provide a motivation for
studying all this (new) material, he said: “Think about a non-commutative generalization of this
structure!” (Which eventually I did.) During the absence of Prof. Vaida, Prof. George Georgescu
was of great help, indicating more bibliography on the matter, and always open to discuss related
topics with me. On the other hand, Prof. Cazanescu introduced me to symmetric strict monoidal
categories, and the model he developed with Gheorghe Stefanescu.
During the whole period spent in the Faculty, since 1981, I benefited from attending numerous
scientific seminars. In the eighties there was a seminar on Information Theory, which tried to
keep alive the interest for this area after the departure of Silviu Guiasu. Also in the eighties, I
attended the seminar conducted by Alexandru Brezuleanu, whom I knew and with whom I
worked just for a short period before his untimely death. There was also a seminar initiated by
Prof. Cazanescu and Razvan Diaconescu which I attended. And sometime after (perhaps ’92), the
“Alexandru Brezuleanu” seminar was initiated by Prof. G. Georgescu, seminar which became
over the years the GLAU seminar (Group of Logic and Universal Algebra).
In 2002 I had the great opportunity to receive a sabbatical grant from the Spanish Ministry of
Education and Sports, and thus to spend 18 months at the Rovira i Virgili University, in
Tarragona, Spain. I was responsible for the Course on Marcus Contextual Grammars held as part
of the 1st PhD School of Formal Languages and Applications. I had the opportunity to meet and
know people like Arto Salomaa, Gregorz Rozenberg, Tom Head (to name only a few giant
names). The research interests of the group ranged from formal and natural languages to natural
computing (computing models inspired by biological mechanisms), and for the latter, in particular
membrane computing, developed by Gheorghe Paun who at that time was working there. I started
working in this fascinating area, and continued to do so with the Natural Computing group at the
University of Seville. A selection of papers in this area, all published in 2003, and some good
luck, made me the recipient of the “Grigore C. Moisil” award of the Romanian Academy,
bringing thus his name and his memory closer to me than ever expected. My journey to meet his
name on the award has been shaped and channeled by all the people with Moisil number 1 I
mentioned above (and probably more), by the entire heritage he left behind as a mathematician,
as a leader, and as a human being.
The footprints. The list of papers I authored or co-authored below, is organized by themes
which, in a minor key, relate to some major themes in Moisil’s life and work.
Algebras for many-valued logics
(1) On Algebras with Implications, Categorically Equivalent to Pseudo-MV Algebras, in
“Information technology”, Proceedings of the 4th International Symposium on Economic
Informatics, May 1999, INFOREC Printing House, Bucharest, Romania 1999, p. 912-916
(2) Pseudo-Wajsberg Algebras, Multi. Val. Logic, Nrs. 1-2, 2001, Vol. 6, p. 67-88
(3) The Lattice Structure of Pseudo-Wajsberg Algebras, J.UCS vol. 6, nr. 1, January 28,
2000, p. 22-38
(4) Weak Pseudo-Wajsberg Algebras, The Fifth International Conference FSTA 2000 On
Fuzzy Sets Theory And Its Applications, editors F. Chovanec and E. Rybarikova, p. 6062
(5) Weak Pseudo-Wajsberg and Weak Pseudo-MV Algebras, Soft Computing, Vol. 5 (2001)
Issue 5, p. 334-346
Math (structural)
(6) The Samuel Stratification of the Discriminant is Whitney Regular, Geometriae Dedicata
17, p. 181-184 (1984), (with A. Dimca)(under the name Rodica Rosian)
(7) Cauchy Structures and the Kerekjarto-Stoilow Compactification, Demonstratio
Matematica, Vol. XXI, No. 3 (1988), p. 685-695
(8) A Localization Theorem for Topological Categories, Stud. Cerc. Mat., vol. 42 (1990)1, p.
3-8
Theoretical CS with tools from Category Theory
(9) Initial and Final Congruences, Acta Cybernetica, vol. 10, nr. 1 (1992), p. 199-215 (with
V.E. Cazanescu)
(10)
On Canonical Fixed Points, Annals of the U.B., Mathematics-Informatics Series,
Vol. 41, No. 2, 1992, p. 55-60
(11)
The Naturality of the Semantics of Recursion, in "Mathematical Linguistics and
Related Topics" (Gh.Paun ed.), Ed. Acad. Rom. 1995, p.44-52
Formal Languages (Contextual Languages and others) with algebraic tools
(12)
Marcus Contextual Languages and their Cut-and-Paste Properties, in "Rough
Sets and Current Trends in Computing" (L. Polkowski, A. Skowron eds.) RSCTC '98
Proceedings, Springer Lecture Notes in Computer Science 1424, 1998, p. 99-106
(13)
Characterizing Contextual Languages with Fixed-Point Equations, Annals of the
U.B., Mathematics-Informatics Series, Vol. 47, 1998, p. 41-49
(14)
Selection Mechanisms Between Strings and Contexts: an Equational Approach,
MFCS '98 Workshop "Mathematical Linguistics" Proceedings, Brno, July 1998, p. 23-44.
(15)
Cut-and Paste Languages, Grammars, vol.2, nr. 3, 1999, p. 179-188
(16)
Some Algebraic Properties of Contexts and Their Applications to Contextual
Languages, in "Where Mathematics, Computer Science, Linguistics and Biology Meet" ,
Carlos Martin-Vide and Victor Mitrana editors, Kluwer Academic Publ., Dordrecht,
London, Boston, 2001, p. 219-226
(17)
Marcus Contextual Grammars, chapter 17 of "Formal Languages and
Applications" (Carlos Martin-Vide, V. Mitrana, Gh. Paun Eds.), (ISSN 1434-9922, ISBN
3-540-20907-7, 620 p.) Vol. 148 Studies in Fuzziness and Soft Computing Series, Editor
in Chief Janusz Kacprzyk, Springer Verlag, Berlin, Heilderberg, New York, 2004, p.
335-366
(18)
On Total Contextual Grammars with Restricted Choice, Fundamenta
Informaticae, 64, 1-4(2005), 79-91 (with Radu Gramatovici)
Interdisciplinary, miscellanea
(19)
A topological approach to learning processes, Foundations of Control
Engineering, vol. 2, no. 3 (1977), (with M. Malita)
(20)
Minimum Entropy Deconvolution, (in Romanian) Buletin Tehnico-Stiintific
IPGGH, vol. 1 Ianuarie-Martie 1980, p. 49-64 (under the name Rodica Rosian)
(21)
Change, Entropy, Information and Communication, Rev. Roum. De
Linguistique, vol. XXXII (1987), CLTA vol. 24 (1987), no.1, p. 17-36
(22)
Temporality, Development and Human Communication, Rev. Roum. De
Linguistique, vol. XXIII (1988), CLTA vol. 25 (1988), no. 2, p. 117-136
(23)
A Semiotic Approach to Knowledge Processing Systems, Proc. of the Seventh
International Congress of Cybernetics and Systems, London, September 1987, ed. J.
Rose, Thales Publications, Lytham, St. Annes, England, vol. 2, p. 941-944 (with M.
Malita)
(24)
Categories in the Study of Communication Processes and Meaning Generation,
in "Signs of Humanity" / "L'Homme et ses Signes" Proceedings of the Fourth
International Congress / Actes du Quatrieme Congres Mondial, International Association
for Semiotic Studies / Association Internationale du Semiotique, Barcelone - Perpignan
1989, 03-03/06-04, edited by Michel Balad et Janice Delledale-Rhodes, general editor
Gerard Delledale, Mouton DeGruyter, Berlin, New York, 1993, p.181-186
Natural Computing
(25)
Modeling DNA Recombinant Behavior with Fixed-Point Equations, in
"Computing with Bio-Molecules: Theory and Experiments" (Gh. Paun ed.), SpringerVerlag, Singapore 1998, p. 340-352
(26)
Generating P Systems with Contextual Grammars, Pre-Proceedings of the
Workshop on Membrane Computing (WMC-CdA2002), editors G. Paun, C. Zandron, p.
119-144 (with Carlos Martin-Vide)
(27)
Dynamic P Systems, in "Membrane Computing", International Workshop, WMCCdeA 2002, Curtea de Arges, Romania, August 2002, Revised Papers, (G. Paun, G.
Rozenberg, A. Salomaa, C. Zandron eds.), LNCS 2597, Springer 2003, p. 146-186 (with
Carlos Martin-Vide)
(28)
An Application of Dynamic P Systems: Generating Context-Free Languages, in
"Membrane Computing", International Workshop, WMC-CdeA 2002, Curtea de Arges,
Romania, August 2002, Revised Papers, (G. Paun, G. Rozenberg, A. Salomaa, C.
Zandron eds.), LNCS 2597, Springer, 2003 p. 90-106 (with Gemma Bel-Enguix, Matteo
Cavalliere, Radu Gramatovici, Carlos Martin-Vide)
(29)
Simple Circular H Systems, ROMJIST, Vol. 6, Numbers 1-2 (2003), p. 121-134
(with K. G. Subramanian)
(30)
Another Class of Semi-Simple Splicing Systems, presented at the Primer
Congresso/First Joint Meeting RSME-AMS, Seville, 18-21 June 2003, Section BioMolecular Computation (with Carlos Martin-Vide, K. G. Subramanian)
(31)
Array-Rewriting P Systems, in Technical Report URV No. 26/03: Matteo
Cavaliere, Carlos Martin-Vide, Gheorghe Paun (Editors): Brainstorming Week on
Membrane Computing, Tarragona, Feb. 5-11, 2003, p. 118-134 (with M. Mutyam, G.
Paun, K.G. Subramanian)
(32)
Generating Picture Languages with P Systems, in Technical Report URV No.
26/03: Matteo Cavaliere, Carlos Martin-Vide, Gheorghe Paun (Editors): Brainstorming
Week on Membrane Computing, Tarragona, Feb. 5-11, 2003, p. 85-100 (with R.
Gramatovici, N. Jonoska, K.G. Subramanian)
(33)
P Systems with Communication for Static Sorting, in Technical Report URV No.
26/03: Matteo Cavaliere, Carlos Martin-Vide, Gheorghe Paun (Editors): Brainstorming
Week on Membrane Computing, Tarragona, Feb. 5-11, 2003, p. 101-117 (with Carlos
Martin-Vide)
(34)
Array-Rewriting P Systems, Natural Computing 2 (2003), p. 229-249 (with M.
Mutyam, G. Paun, K.G. Subramanian)
(35)
Tissue-like P Systems with Active Membranes for Picture Generation,
Fundamenta Informaticae 56 (2003), 311-328 (with R. Gramatovici, N. Jonoska, K.G.
Subramanian)
(36)
P Systems for Tiling Rectangular Pictures, in Technical Report URV No. 28/03:
Artiom Alhazov, Carlos Martin-Vide, Gheorghe Paun (Eds.): Workshop on Membrane
Computing, WMC 2003; Tarragona, July 17-22, 2003, p. 133-144 (with R. Gramatovici,
N. Jonoska)
(37)
Simulating Boolean Circuits with P Systems, in Technical Report URV No.
28/03: Artiom Alhazov, Carlos Martin-Vide, Gheorghe Paun (Eds.): Workshop on
Membrane Computing, WMC 2003; Tarragona, July 17-22, 2003, p. 145-160 (with D.
Sburlan)
(38)
On Some Classes of Splicing Languages, in "Aspects of Molecular Computing:
Essays in Honor of the 70th Birthday of Tom Head" (N. Jonoska, Gh. Paun, Gr.
Rozenberg Eds.), LNCS 2950, Springer Verlag, Berlin, 2004, p. 84-105 (with Carlos
Martin-Vide, K.G. Subramanian)
(39)
Tiling Rectangular Pictures with P Systems, in "Membrane Computing:
International Workshop WMC 2003, Tarragona, Spain (Carlos Martin-Vide, Gh. Paun,
Gr. Rozenberg, A. Salomaa Eds.), LNCS 2933, Springer Verlag, Berlin, 2004, p. 88-103
(with R. Gramatovici, N. Jonoska)
(40)
Simulating Boolean Circuits with P Systems, in "Membrane Computing:
International Workshop WMC 2003, Tarragona, Spain (Carlos Martin-Vide, Gh. Paun,
Gr. Rozenberg, A. Salomaa Eds.), LNCS 2933, Springer Verlag, Berlin, 2004, p. 104-122
(with D. Sburlan)
(41)
Simulating Shuffle--Exchange Networks with P Systems, in Proceedings of the
Second Brainstorming Week on Membrane Computing, Report RGNC 01/04, 2004, (G.
Paun, A. Riscos, F. Sancho and A. Romero Eds.), p. 117-129 (with Mario J. Perez
Jimenez)
(42)
A Perfect Shuffle Algorithm for Reduction Processes and its Simulation with P
Systems, in Proceedings of ICCC 2004, Baile Felix Spa-Oradea, Romania, (I. Dzitac, T.
Maghiar, C. Popescu Eds.) p. 92-97 (with Mario J. Perez Jimenez)
(43)
On Two-Dimensional Mesh Networks and Their Simulation with P Systems, in
Membrane Computing, 5th International Workshop, WMC 2004, Milan, Italy, June 14-16,
2004, Revised Selected and Invited Papers, (G. Mauri, G. Paun, M. J. Perez Jimenez, G.
Rozenberg, A. Salomaa Eds.) LNCS 3365, Springer 2005, ISBN 3-540-25080, 259-277
(with Mario J. Perez Jimenez)
(44)
Simulating a Class of Parallel Architectures: A Broader Perspective, in "Cellular
Computing (Complexity Aspects)" ESF PESC Exploratory Workshop, Sevilla, Spain,
January 31 - February 2, 2005, (M.A. Gutierrez-Naranjo et al, eds), Fenix Editora,
Sevilla, 2005, p. 131-148.
(45)
On Simulating a Class of Parallel Architectures, International Journal of
Foundations of Computer Science, Volume 17, Number 1, February 2006, p.91-110 (with
Mario J. Perez Jimenez)
(46)
Rewriting in P Systems: an Algebraic Approach, in "Fourth Brainstorming Week
on Membrane Computing", Sevilla, Spain, Jan. 30 - Febr. 3, 2006, Vol. I (M.A.
Gutierrez-Naranjo et al, eds), Fenix Editora, Sevilla, 2006, p. 165-168.
(47)
An Algebraic Characterization of Semi-Simple Splicing, Fundamenta
Informaticae 73 (1-2) (2006), p. 19-25
(48)
Simulating the Bitonic Sort Using P Systems, in "Membrane Computing. 8th
International Workshop, WMC2007, Thessaloniki, Greece, June 2007. Revised, Selected,
and Invited Papers", LNCS 4860 (G. Eleftherakis et. al. eds.) Springer, 2007, pag. 172192.