Results 1 
3 of
3
TAGED Approximations for Temporal Properties ModelChecking ⋆
"... Abstract. This paper investigates the use of tree automata with global equalities and disequalities (TAGED for short) in reachability analysis over term rewriting systems (TRSs). The reachability problem being in general undecidable on non terminating TRSs, we provide TAGEDbased construction, and th ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
Abstract. This paper investigates the use of tree automata with global equalities and disequalities (TAGED for short) in reachability analysis over term rewriting systems (TRSs). The reachability problem being in general undecidable on non terminating TRSs, we provide TAGEDbased construction, and then design approximationbased semidecision procedures to modelcheck useful temporal patterns on in nite state rewriting graphs. To show that the above TAGEDbased construction can be e ectively carried out, complexity analysis for rewriting TAGEDde nable languages is given. 1
Controlled Term Rewriting ⋆
, 2011
"... Abstract. Motivated by the problem of verification of imperative tree transformation programs, we study the combination, called controlled term rewriting systems (CntTRS), of term rewriting rules with constraints selecting the possible rewrite positions. These constraints are specified, for each rew ..."
Abstract
 Add to MetaCart
Abstract. Motivated by the problem of verification of imperative tree transformation programs, we study the combination, called controlled term rewriting systems (CntTRS), of term rewriting rules with constraints selecting the possible rewrite positions. These constraints are specified, for each rewrite rule, by a selection automaton which defines a set of positions in a term based on tree automata computations. We show that reachability is PSPACEcomplete for socalled monotonic CntTRS, such that the size of every lefthandside of every rewrite rule is larger or equal to the size of the corresponding righthandside, and also for the class of contextfree noncollapsing CntTRS, which transform ContextFree (CF) tree language into CF tree languages. When allowing sizereducing rules, reachability becomes undecidable, even for flat CntTRS (both sides of rewrite rules are of depth at most one) when restricting to words (i.e. function symbols have arity at most one), and for ground CntTRS (rewrite rules have no variables). We also consider a restricted version of the control such that a position is selected if the sequence of symbols on the path from that position to the root of the tree belongs to a given regular language. This restriction enables decision results in the above cases.
Certificates for Tree Automata Completion ⋆
"... Abstract. We consider the problem of certifying the correctness of a protocol or security API through a formal, machinecheckable proof. To this aim, we reexamine the completion algorithm for tree automata and term rewriting systems, that computes an overapproximation of regular sets of terms up t ..."
Abstract
 Add to MetaCart
Abstract. We consider the problem of certifying the correctness of a protocol or security API through a formal, machinecheckable proof. To this aim, we reexamine the completion algorithm for tree automata and term rewriting systems, that computes an overapproximation of regular sets of terms up to rewriting. We then define a procedure to certify, via a proof, that the result of the completion is indeed correct. Hence, with our procedure, a program verification tool that uses the completion algorithm can certify its results. As a consequence, we do not need to regard the tool as a trusted component of the verification process. We discuss on our experiments in which we automatically generated security proofs for some selected protocols. 1