Publication Details
What else is decidable about integer arrays?
mathematical logic, arrays, decidability, decision procedure, formal verification, automata
This report is the full version of the corresponding FOSSCAS'08 paper, including full proofs of the achived results. In the work, we introduce a new decidable logic for reasoning about infinite arraysof integers. The logic is in the $\exists^* \forall^*$ first-orderfragment and allows (1) Presburger constraints on existentiallyquantified variables, (2) difference constraints as well as periodicityconstraints on universally quantified indices, and (3) differenceconstraints on values. In particular, using our logic, one can expressconstraints on consecutive elements of arrays (e.g., $\forall i ~.~ 0\leq i < n \rightarrow a[i+1]=a[i]-1$) as well as periodic facts(e.g., $\forall i ~.~ i \equiv_2 0 \rightarrow a[i] = 0$). The decisionprocedure follows the automata-theoretic approach: we translateformulae into a special class of B\"uchi counter automata such that anymodel of a formula corresponds to an accepting run of an automaton, andvice versa. The emptiness problem for this class of counter automata isshown to be
decidable as a consequence of earlier results on counter automata with a flat control structure and transitions based on
difference constraints.
@techreport{BUT63915,
author="Peter {Habermehl} and Iosif {Radu} and Tomáš {Vojnar}",
title="What else is decidable about integer arrays?",
year="2008",
publisher="VERIMAG",
address="TR-2007-8, Grenoble",
pages="36",
url="http://www.fit.vutbr.cz/~vojnar/Publications/hiv-arrays-tr-07.pdf"
}