|Résumé||We present a preliminar version of the program "LALBLC" (i.e. LA=LB? Let us Compute).
The equivalence problem for dpda consists in deciding, for two given deterministic pushdown automata A,B, whether they recognize the same language. It was proved in [TCS 2001, G.S.] that this problem is decidable by means of some complete proof systems.
The program LALBLC gives, in some sense, life to the above completeness proof: on an input A,B, the program computes either a proof of their equivalence (w.r.t. to the system D5 of the above reference) or computes a witness of their non-equivalence (i.e. a word that belongs to the symmetric difference of the two languages).
We shall outline the main mathematical objects that are manipulated as well as the main functions performed over these objects. We shall also describe some experimental results obtained so far.
The talk is based on an ongoing, joint, work with P. Henry. |