Jobs/M2 AD 2014 minimisation-automates


Minimization of automata
Reference id

M2 AD 2014 minimisation-automates


5 - 6 months in 2014

Research field

Automata Theory

Related project



Akim Demaille

General presentation of the field

The classical theory of automata, of transducers and of rational expressions, admits a very elegant and extremely useful extension (eg, in natural language processing) taking into account the concept of weighting. The weights are then taken in a semi-ring, which can be classical (⟨B, ∨, ∧⟩, ⟨Z, +, ×⟩, ⟨Q, +, ×⟩, etc..), tropical (⟨Z min, +⟩, etc..), or yet of another type (eg rational expressions). Vaucanson 2 is a project with financial aid from ANR (National Research Agency) developed in partnership between Telecom ParisTech (Jacques Sakarovitch), LaBRI (Sylvain Lombardy) and the LRDE (Alexandre Duret-Lutz and Akim Demaille). It is a platform for the manipulation of automata, transducers and weighted rational expressions. It is written in C++11 avoiding the classical object-oriented programming in favor of generic programming (template) for more performance.


The minimization of an automaton consists of its "optimization": it means building the smallest equivalent automaton. There are many algorithms for the minimization of automata, whose fields of application and performance vary. The task of the intern will be to implement some of these algorithms in Vaucanson 2, to optimize them, and to conduct a comparative study of their performance. These results will provide an adaptive approach that selects the algorithm to be applied depending on the profile of the automaton / transducer.

Benefit for the candidate

Some references

Place LRDE: How to get to us

800€ euros gross/month

Future work opportunities

If you have performed the internship satisfactorily, we would like it to be followed by a PhD thesis.


<akim . demaille at lrde . epita . fr>