8 papers
Robust Algebraic Theories of Triangle Graphs
Marius Bozga, Radu Iosif, Florian Zuleger
Triangle graphs are graphs of tree-width at most three in which every edge belongs to a triangle. This class encompasses well-known graph families such as Apollonian networks. We a…
Regular Grammars as Effective Representations of Recognizable Sets of Series-Parallel Graphs
Marius Bozga, Radu Iosif, Florian Zuleger
Series-parallel (SP) graphs are binary edge-labeled graphs with a designated source and target vertex, built using serial and parallel composition. A set of graphs is recognizable…
Characterizations of Monadic Second Order Definable Context-Free Sets of Graphs
Radu Iosif, Florian Zuleger
We give a characterization of the sets of graphs that are both definable in Counting Monadic Second Order Logic (CMSO) and context-free, i.e., least solutions of Hyperedge-Replacem…
Iterating Non-Aggregative Structure Compositions
Marius Bozga, Radu Iosif, Florian Zuleger
An aggregative composition is a binary operation obeying the principle that the whole is determined by the sum of its parts. The development of graph algebras, on which the theory…
Proceedings 9th edition of Working Formal Methods Symposium
Andrei Arusoaie, Horaţiu Cheval, Radu Iosif
This volume contains the proceedings of the 9th Working Formal Methods Symposium, which was held at the Alexandru Ioan Cuza University, IaÅi, Romania on September 17-19, 2025.
Regular Grammars for Sets of Graphs of Tree-Width 2
Marius Bozga, Radu Iosif, Florian Zuleger
Regular word grammars are restricted context-free grammars that define all the recognizable languages of words. This paper generalizes regular grammars from words to certain classe…